diff --git a/codego/.gitignore b/codego/.gitignore
new file mode 100644
index 0000000..38df4b3
--- /dev/null
+++ b/codego/.gitignore
@@ -0,0 +1,25 @@
+*
+!/.gitignore
+
+!/data.env
+!/README.md
+!/run.sh
+!/test.sh
+
+## Go Source
+!/aussagenlogik
+!/aussagenlogik/rekursion
+!/aussagenlogik/schema
+!/aussagenlogik/syntaxbaum
+!/core
+!/core/environment
+!/core/utils
+!/grammars
+!/**/*.go
+!/go.mod
+!/go.sum
+
+## Für Erzeugung von Grammatiken:
+!/grammars/antlr.jar
+!/grammars/README.md
+!/grammars/*.g4
diff --git a/codego/README.md b/codego/README.md
new file mode 100644
index 0000000..9fb1b5e
--- /dev/null
+++ b/codego/README.md
@@ -0,0 +1,64 @@
+# Code in golang #
+
+Die Inhalte dieses Ordners sind absolut **kein Pflichtbestandteil** des Kurses.
+
+Diese dienen nur zur Demonstration / konkreten Verwirklichung von Verfahren, die im Kurs auftauchen. Für Wissbegierige mit auch grundlegenden Programmierkenntnissen bietet sich dies als Möglichkeit an, um sich selbst zu überzeugen, dass strukturelle Rekursion funktioniert.
+
+Der Gebrauch dieser Skripte unterliegt der Eigenverantwortung von Studierenden.
+
+Da ich kein Informatiker bin, sind auch einige Aspekt bestimmt nicht optimal programmiert/strukturiert.
+
+## Systemvoraussetzungen ##
+
+- bash (auch bash-for-windows).
+- golang (mind. 1.6.x)
+
+## Voreinstellungen ##
+
+- In einer bash-console zu diesem Ordner navigieren und folgenden Befehl ausführen:
+    ```bash
+    chmod +x run.sh test.sh
+    ## oder
+    chmod +x *.sh
+    ```
+- In `run.sh` gibt es eine Zeile, die zur Kompilierung des Go-Projektes notwendigen Module über **go** installieren lässt. (Die Liste der Packages findet man in der Datei `requirements`). Diese Zeile kann man ruhig nach der ersten Ausführung rauskommentieren.
+
+## Daten ##
+
+In `data.env` kann man Daten (aktuell: auszuwertenden Ausdruck + Interpretation/Modell) eintragen. Man beachte dabei die Syntax.
+
+## Gebrauchshinweise ##
+
+In einer bash-console zu diesem Ordner navigieren und
+```bash
+./run.sh
+## oder
+go build main.go && ./main
+```
+ausführen.
+
+## Offene Challenges ##
+
+In der Datei `aussagenlogik/rekursion.go` (relativ zu diesem Ordner) findet man mehrere leere Methoden (mit dem Kommentar `// Herausforderung...`). Wer es mag, kann versuchen, an seinem Rechner diese Methoden zu definieren und auszuprobieren.
+
+### Händisch testen ###
+
+Probiere es mit Stift-und-Zettel und anhand von Beispielen die Werte händisch zu berechnen. Vergleiche dies mit den durch den Code rekursiv berechneten Werten. Stimmt alles überein?
+
+### Automatisierte Tests ###
+
+Wer etwas standardisierter seine Methoden testen will, kann automatisiertes Testing tätigen. Diese Tests existieren parallel zu jedem Modul und folgen dem Namensschema `..._test.go`.
+
+- In der Console (wenn noch nicht geschehen) folgenden Befehl einmalig ausführen:
+    ```bash
+    chmod +x test.sh
+    ```
+- In `aussagenlogik/rekursion/rekursion_test.go` beim relevanten Testteil eine oder mehrere der Zeilen
+    ```go
+    test.Skip("Methode noch nicht implementiert")
+    ```
+    rauskommentieren/löschen.
+
+Jetzt `test.sh` ausführen. Die unittests testen Methoden gegen mehrere vorkonstruierte Testfälle samt erwarteten Ergebnissen geprüft. Sollten einige Tests scheitern, dann Fehlermeldung durchlesen, und Methode entsprechend der Kritik überarbeiten.
+
+Die geschriebenen Unittests sind natürlich nicht ausführlich. Man kann diese nach Bedarf ergänzen. Am sinnvollsten baut man welche, die wirklich scheitern können, sonst sagen die Tests nichts aus.
diff --git a/codego/aussagenlogik/rekursion/rekursion.go b/codego/aussagenlogik/rekursion/rekursion.go
new file mode 100644
index 0000000..7164228
--- /dev/null
+++ b/codego/aussagenlogik/rekursion/rekursion.go
@@ -0,0 +1,82 @@
+package rekursion
+
+import (
+	"log"
+	"logik/aussagenlogik/syntaxbaum"
+	"logik/core/utils"
+)
+
+/* ---------------------------------------------------------------- *
+ * EXPORTS
+ * ---------------------------------------------------------------- */
+
+func RekursivEval(tree syntaxbaum.SyntaxBaum, I []string) int {
+	var children = tree.GetChildren()
+	switch tree.Kind {
+	case "atom", "generic":
+		if utils.StrListContains(I, tree.Expr) {
+			return 1
+		}
+		return 0
+	case "taut":
+		return 1
+	case "contradiction":
+		return 0
+	case "not":
+		subtree0, _ := tree.GetChild()
+		val0 := RekursivEval(subtree0, I)
+		return 1 - val0
+	case "and2":
+		val0 := RekursivEval(children[0], I)
+		val1 := RekursivEval(children[1], I)
+		return utils.Min2(val0, val1)
+	case "and":
+		var val = 1
+		for _, subtree := range children {
+			var val_ = RekursivEval(subtree, I)
+			val = utils.Min2(val, val_)
+		}
+		return val
+	case "or2":
+		val0 := RekursivEval(children[0], I)
+		val1 := RekursivEval(children[1], I)
+		return utils.Max2(val0, val1)
+	case "or":
+		var val = 0
+		for _, subtree := range children {
+			var val_ = RekursivEval(subtree, I)
+			val = utils.Max2(val, val_)
+		}
+		return val
+	case "implies":
+		val0 := RekursivEval(children[0], I)
+		val1 := RekursivEval(children[1], I)
+		if val0 <= val1 {
+			return 1
+		}
+		return 0
+	default:
+		log.Fatal("Could not evaluate expression!")
+		return 0
+	}
+}
+
+func RekursivAtoms(tree syntaxbaum.SyntaxBaum) []string {
+	// Herausforderung: schreibe diese Funktion!
+	return []string{}
+}
+
+func RekursivDepth(tree syntaxbaum.SyntaxBaum) int {
+	// Herausforderung: schreibe diese Funktion!
+	return 0
+}
+
+func RekursivLength(tree syntaxbaum.SyntaxBaum) int {
+	// Herausforderung: schreibe diese Funktion!
+	return 0
+}
+
+func RekursivParentheses(tree syntaxbaum.SyntaxBaum) int {
+	// Herausforderung: schreibe diese Funktion!
+	return 0
+}
diff --git a/codego/aussagenlogik/rekursion/rekursion_test.go b/codego/aussagenlogik/rekursion/rekursion_test.go
new file mode 100644
index 0000000..b38cf58
--- /dev/null
+++ b/codego/aussagenlogik/rekursion/rekursion_test.go
@@ -0,0 +1,287 @@
+package rekursion_test
+
+/* ---------------------------------------------------------------- *
+ * UNIT TESTING
+ * ---------------------------------------------------------------- */
+
+import (
+	"logik/aussagenlogik/rekursion"
+	"logik/aussagenlogik/schema"
+	"logik/aussagenlogik/syntaxbaum"
+	"logik/core/utils"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+/* ---------------------------------------------------------------- *
+ * TESTCASE eval(·, ·)
+ * ---------------------------------------------------------------- */
+
+func TestRekursivEvalLiteral(test *testing.T) {
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var I []string
+	var val int
+	tree, _ = schema.ParseExpr("A0")
+	I = []string{"A0"}
+	val = rekursion.RekursivEval(tree, I)
+	assert.Equal(val, 1)
+	tree, _ = schema.ParseExpr("A0")
+	I = []string{}
+	val = rekursion.RekursivEval(tree, I)
+	assert.Equal(val, 0)
+	tree, _ = schema.ParseExpr("! A0")
+	I = []string{"A0"}
+	val = rekursion.RekursivEval(tree, I)
+	assert.Equal(val, 0)
+	tree, _ = schema.ParseExpr("! A0")
+	I = []string{}
+	val = rekursion.RekursivEval(tree, I)
+	assert.Equal(val, 1)
+}
+
+func TestRekursivEvalComplex1(test *testing.T) {
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var I []string
+	var val int
+	tree, _ = schema.ParseExpr("( ! A0 || (( A0 && A3 ) || A2 ))")
+	I = []string{"A0", "A2"}
+	val = rekursion.RekursivEval(tree, I)
+	assert.Equal(val, 1)
+	I = []string{"A0", "A3"}
+	val = rekursion.RekursivEval(tree, I)
+	assert.Equal(val, 1)
+	I = []string{"A0"}
+	val = rekursion.RekursivEval(tree, I)
+	assert.Equal(val, 0)
+	I = []string{"A4", "A8"}
+	val = rekursion.RekursivEval(tree, I)
+	assert.Equal(val, 1)
+}
+
+func TestRekursivEvalComplex2(test *testing.T) {
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var I []string
+	var val int
+	tree, _ = schema.ParseExpr("( ! A0 || (( A0 && A3 ) || ! A2 ))")
+	I = []string{"A0", "A2"}
+	val = rekursion.RekursivEval(tree, I)
+	assert.Equal(val, 0)
+	I = []string{"A0", "A3"}
+	val = rekursion.RekursivEval(tree, I)
+	assert.Equal(val, 1)
+}
+
+/* ---------------------------------------------------------------- *
+ * TESTCASE Atoms(·)
+ * ---------------------------------------------------------------- */
+
+func TestRekursivAtomsNoduplicates(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val []string
+	tree, _ = schema.ParseExpr("( A4 && ( A4 || A4 ))")
+	val = rekursion.RekursivAtoms(tree)
+	var n int = len(utils.FilterStrings(&val, func(x string) bool { return x == "A4" }))
+	assert.Equal(n, 1, "Atome dürfen nicht mehrfach vorkommen!")
+}
+
+func TestRekursivAtomsNononatoms(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	test.Skip("Syntax for generic expressions in ANTLR4 g4 needs to be implemented.")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val []string
+	tree, _ = schema.ParseExpr("( {F} || A3 )")
+	val = rekursion.RekursivAtoms(tree)
+	utils.SortStrings(&val)
+	assert.NotContains(val, "F", "Nichtatomare Formeln dürfen nicht vorkommen!")
+}
+
+func TestRekursivAtomsCalc1(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val []string
+	tree, _ = schema.ParseExpr("A0")
+	val = rekursion.RekursivAtoms(tree)
+	utils.SortStrings(&val)
+	assert.Equal(val, []string{"A0"})
+}
+
+func TestRekursivAtomsCalc2(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val []string
+	tree, _ = schema.ParseExpr("((( ! A8 && A3 ) || A4 ) && A0 )")
+	val = rekursion.RekursivAtoms(tree)
+	utils.SortStrings(&val)
+	assert.Equal(val, []string{"A0", "A3", "A4", "A8"})
+}
+
+/* ---------------------------------------------------------------- *
+ * TESTCASE depth(·, ·)
+ * ---------------------------------------------------------------- */
+
+func TestRekursivDepthCalc1(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("A0")
+	val = rekursion.RekursivDepth(tree)
+	assert.Equal(val, 0)
+}
+
+func TestRekursivDepthCalc2(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("!! A8")
+	val = rekursion.RekursivDepth(tree)
+	assert.Equal(val, 2)
+}
+
+func TestRekursivDepthCalc3(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("( ! A0 && A3 )")
+	val = rekursion.RekursivDepth(tree)
+	assert.Equal(val, 2)
+}
+
+func TestRekursivDepthCalc4(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("((( ! A0 && A3 ) || A4 ) && A8 )")
+	val = rekursion.RekursivDepth(tree)
+	assert.Equal(val, 4)
+}
+
+func TestRekursivDepthCalc5(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("! ((( ! A0 && A3 ) || A4 ) && A8 )")
+	val = rekursion.RekursivDepth(tree)
+	assert.Equal(val, 5)
+}
+
+/* ---------------------------------------------------------------- *
+ * TESTCASE length(·)
+ * ---------------------------------------------------------------- */
+
+func TestRekursivLengthCalc1(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("A0")
+	val = rekursion.RekursivLength(tree)
+	assert.Equal(val, 1)
+}
+
+func TestRekursivLengthCalc2(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("!! A8")
+	val = rekursion.RekursivLength(tree)
+	assert.Equal(val, 3)
+}
+
+func TestRekursivLengthCalc3(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("( ! A0 && A3 )")
+	val = rekursion.RekursivLength(tree)
+	assert.Equal(val, 4)
+}
+
+func TestRekursivLengthCalc4(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("((( ! A0 && A3 ) || A4 ) && A8 )")
+	val = rekursion.RekursivLength(tree)
+	assert.Equal(val, 8)
+}
+
+func TestRekursivLengthCalc5(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("! ((( ! A0 && A3 ) || A4 ) && A8 )")
+	val = rekursion.RekursivLength(tree)
+	assert.Equal(val, 9)
+}
+
+/* ---------------------------------------------------------------- *
+ * TESTCASE #Parentheses(·)
+ * ---------------------------------------------------------------- */
+
+func TestRekursivParenthesesCalc1(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("A0")
+	val = rekursion.RekursivParentheses(tree)
+	assert.Equal(val, 0)
+}
+
+func TestRekursivParenthesesCalc2(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("!! A8")
+	val = rekursion.RekursivParentheses(tree)
+	assert.Equal(val, 0)
+}
+
+func TestRekursivParenthesesCalc3(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("( ! A0 && A3 )")
+	val = rekursion.RekursivParentheses(tree)
+	assert.Equal(val, 2)
+}
+
+func TestRekursivParenthesesCalc4(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("((( ! A0 && A3 ) || A4 ) && A8 )")
+	val = rekursion.RekursivParentheses(tree)
+	assert.Equal(val, 6)
+}
+
+func TestRekursivParenthesesCalc5(test *testing.T) {
+	test.Skip("Methode noch nicht implementiert")
+	var assert = assert.New(test)
+	var tree syntaxbaum.SyntaxBaum
+	var val int
+	tree, _ = schema.ParseExpr("! ((( ! A0 && A3 ) || A4 ) && A8 )")
+	val = rekursion.RekursivParentheses(tree)
+	assert.Equal(val, 6)
+}
diff --git a/codego/aussagenlogik/schema/schema.go b/codego/aussagenlogik/schema/schema.go
new file mode 100644
index 0000000..5fa3e5d
--- /dev/null
+++ b/codego/aussagenlogik/schema/schema.go
@@ -0,0 +1,175 @@
+package schema
+
+import (
+	"errors"
+	"logik/aussagenlogik/syntaxbaum"
+	parser "logik/grammars/aussagenlogik"
+	"strings"
+
+	"github.com/antlr/antlr4/runtime/Go/antlr"
+)
+
+/* ---------------------------------------------------------------- *
+ * EXPORTS
+ * ---------------------------------------------------------------- */
+
+func ParseExpr(u string) (syntaxbaum.SyntaxBaum, error) {
+	var lexer = createLexer(u)
+	var tokenStream = lexerToTokenStream(lexer)
+	var prs = parser.NewaussagenlogikParser(tokenStream)
+	var t = prs.Start()
+	tree, err := createSyntaxBaum(t, prs)
+	return tree, err
+}
+
+/* ---------------------------------------------------------------- *
+ * PRIVATE
+ * ---------------------------------------------------------------- */
+
+func exprToStream(u string) *antlr.InputStream {
+	return antlr.NewInputStream(u)
+}
+
+func lexerToTokenStream(lexer antlr.Lexer) antlr.TokenStream {
+	return antlr.NewCommonTokenStream(lexer, antlr.TokenDefaultChannel)
+}
+
+func createLexer(u string) antlr.Lexer {
+	stream := exprToStream(u)
+	return parser.NewaussagenlogikLexer(stream)
+}
+
+func createSyntaxBaum(tree antlr.Tree, parser antlr.Parser) (syntaxbaum.SyntaxBaum, error) {
+	var ant = antlrTree{tree: tree, parser: &parser}
+	return ant.toSyntaxBaum()
+}
+
+/* ---------------------------------------------------------------- *
+ * Struct: antlrTree + Methods
+ * ---------------------------------------------------------------- */
+
+type antlrTree struct {
+	tree   antlr.Tree
+	parser *antlr.Parser
+}
+
+func (ant antlrTree) getChildren() []antlrTree {
+	var nodes = ant.tree.GetChildren()
+	var subants = make([]antlrTree, len(nodes))
+	for i, node := range nodes {
+		subants[i] = antlrTree{tree: node, parser: ant.parser}
+	}
+	return subants
+}
+
+func (ant antlrTree) getLabel() string {
+	return antlr.TreesGetNodeText(ant.tree, []string{}, *ant.parser)
+}
+
+func (ant antlrTree) getTextContent() string {
+	var expr string = ant.getLabel()
+	for _, subant := range ant.getChildren() {
+		expr += subant.getTextContent()
+	}
+	return expr
+}
+
+func (ant antlrTree) getTextContentLeaves() string {
+	var expr string = ""
+	var subants = ant.getChildren()
+	if len(subants) == 0 {
+		expr = ant.getLabel()
+	} else {
+		for _, subant := range subants {
+			expr += subant.getTextContent()
+		}
+	}
+	return expr
+}
+
+func (ant antlrTree) toSyntaxBaum() (syntaxbaum.SyntaxBaum, error) {
+	var tree syntaxbaum.SyntaxBaum
+	var err error
+	var label string = ant.getLabel()
+	var subants = ant.getChildren()
+	var nChildren = len(subants)
+
+	switch label {
+	case "start":
+		if nChildren == 1 {
+			return subants[0].toSyntaxBaum()
+		}
+	case "open":
+		if nChildren == 1 {
+			return subants[0].toSyntaxBaum()
+		}
+	case "closed":
+		switch nChildren {
+		case 1:
+			return subants[0].toSyntaxBaum()
+		case 3:
+			return subants[1].toSyntaxBaum()
+		}
+	case "atomic":
+		if nChildren == 1 {
+			subant := subants[0]
+			tree = syntaxbaum.SyntaxBaum{}
+			tree.Expr = subant.getTextContentLeaves()
+			tree.Kind = subant.getLabel()
+			tree.Children = [](*syntaxbaum.SyntaxBaum){}
+			tree.Valence = 0
+			return tree, nil
+		}
+	case "not":
+		if nChildren == 2 { // Children: [NotSymbol, Teilformel]
+			subtree, err := subants[1].toSyntaxBaum()
+			tree = syntaxbaum.SyntaxBaum{}
+			tree.Expr = subants[0].getTextContent() + " " + subtree.Expr
+			tree.Kind = label
+			tree.Children = [](*syntaxbaum.SyntaxBaum){&subtree}
+			tree.Valence = 1
+			return tree, err
+		}
+	case "and2", "and", "or2", "or", "implies":
+		var n int = int((len(subants) + 1) / 2)
+		if nChildren == 2*n-1 && n >= 2 {
+			var isSymb bool = false
+			var subtrees = make([](*syntaxbaum.SyntaxBaum), n)
+			var i int = 0
+			var expr string = ""
+			for _, subant := range subants {
+				if isSymb {
+					expr += " " + subant.getTextContent() + " "
+				} else {
+					subtree, err_ := subant.toSyntaxBaum()
+					if err_ != nil {
+						err = err_
+					}
+					subtrees[i] = &subtree
+					expr += " " + subtree.Expr + " "
+					i++
+				}
+				isSymb = !isSymb
+			}
+			expr = strings.Trim(expr, " ")
+			var lbrace string = "("
+			var rbrace string = ")"
+			// var lbrace string = "( "
+			// var rbrace string = " )"
+			// if strings.HasPrefix(expr, "(") {
+			// 	lbrace = "("
+			// }
+			// if strings.HasSuffix(expr, ")") {
+			// 	rbrace = ")"
+			// }
+			tree = syntaxbaum.SyntaxBaum{}
+			tree.Expr = lbrace + expr + rbrace
+			tree.Kind = label
+			tree.Children = subtrees
+			tree.Valence = n
+			return tree, err
+		}
+	}
+
+	return tree, errors.New("Could not parse expression")
+}
diff --git a/codego/aussagenlogik/schema/schema_test.go b/codego/aussagenlogik/schema/schema_test.go
new file mode 100644
index 0000000..8b175ee
--- /dev/null
+++ b/codego/aussagenlogik/schema/schema_test.go
@@ -0,0 +1,22 @@
+package schema_test
+
+/* ---------------------------------------------------------------- *
+ * UNIT TESTING
+ * ---------------------------------------------------------------- */
+
+import (
+	"logik/aussagenlogik/schema"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+/* ---------------------------------------------------------------- *
+ * TESTCASE ParseExpr
+ * ---------------------------------------------------------------- */
+
+func TestParseExpr(test *testing.T) {
+	var assert = assert.New(test)
+	assert.Equal(0, 0)
+	schema.ParseExpr("A0")
+}
diff --git a/codego/aussagenlogik/syntaxbaum/syntaxbaum.go b/codego/aussagenlogik/syntaxbaum/syntaxbaum.go
new file mode 100644
index 0000000..17eb946
--- /dev/null
+++ b/codego/aussagenlogik/syntaxbaum/syntaxbaum.go
@@ -0,0 +1,136 @@
+package syntaxbaum
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+type SyntaxBaum struct {
+	Kind     string
+	Expr     string
+	Valence  int
+	Children [](*SyntaxBaum)
+}
+
+/* ---------------------------------------------------------------- *
+ * METHODS
+ * ---------------------------------------------------------------- */
+
+func (tree SyntaxBaum) GetChildren() []SyntaxBaum {
+	var n int = tree.Valence
+	var children = make([]SyntaxBaum, n)
+	for i, subtreePtr := range tree.Children {
+		children[i] = *subtreePtr
+	}
+	return children
+}
+
+func (tree SyntaxBaum) GetChild(indexOpt ...int) (SyntaxBaum, error) {
+	var index int = 0
+	if len(indexOpt) > 0 {
+		index = indexOpt[0]
+	}
+	var subtree SyntaxBaum
+	var err error
+	if 0 <= index && index < tree.Valence {
+		subtree = *(tree.Children[index])
+	} else {
+		err = errors.New(fmt.Sprintf("Instance has no child of index %d !", index))
+	}
+	return subtree, err
+}
+
+func (tree SyntaxBaum) Pretty(preindentOpt ...string) string {
+	var preindent string = ""
+	if len(preindentOpt) > 0 {
+		preindent = preindentOpt[0]
+	}
+	return tree.pretty(preindent, "  ", "", 0)
+}
+
+func (tree SyntaxBaum) pretty(preindent string, tab string, prepend string, depth int) string {
+	var indent string = preindent + strings.Repeat(tab, depth)
+	switch tree.Valence {
+	case 0:
+		switch kind := tree.Kind; kind {
+		case "atom", "generic":
+			return indent + prepend + kind + " " + tree.Expr
+		default:
+			return indent + prepend + kind
+		}
+	default:
+		var lines string = indent + prepend + tree.Kind
+		prepend = "|__ "
+		for _, subtree := range tree.Children {
+			lines += "\n" + subtree.pretty(preindent, tab, prepend, depth+1)
+		}
+		return lines
+	}
+}
+
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// METHODS: Recognitong of Formula-Types
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+func (tree SyntaxBaum) isAtom() bool {
+	return tree.Kind == "atom"
+}
+
+func (tree SyntaxBaum) isLiteral() bool {
+	if tree.isAtom() {
+		return true
+	} else if tree.isNegation() {
+		subtree, err := tree.GetChild()
+		if err == nil {
+			return subtree.isAtom()
+		}
+	}
+	return false
+}
+
+func (tree SyntaxBaum) isBeliebig() bool {
+	return tree.Kind == "generic"
+}
+
+func (tree SyntaxBaum) isTrueSymbol() bool {
+	return tree.Kind == "taut"
+}
+
+func (tree SyntaxBaum) isFalseSymbol() bool {
+	return tree.Kind == "contradiction"
+}
+
+func (tree SyntaxBaum) isNegation() bool {
+	return tree.Kind == "not"
+}
+
+func (tree SyntaxBaum) isConjunction() bool {
+	return tree.Kind == "and2"
+}
+
+func (tree SyntaxBaum) isLongConjunction() bool {
+	switch tree.Kind {
+	case "and", "and2":
+		return true
+	default:
+		return false
+	}
+}
+
+func (tree SyntaxBaum) isDisjunction() bool {
+	return tree.Kind == "or2"
+}
+
+func (tree SyntaxBaum) isLongDisjunction() bool {
+	switch tree.Kind {
+	case "or", "or2":
+		return true
+	default:
+		return false
+	}
+}
+
+func (tree SyntaxBaum) isImplication() bool {
+	return tree.Kind == "implies"
+}
diff --git a/codego/core/environment/environment.go b/codego/core/environment/environment.go
new file mode 100644
index 0000000..1b63526
--- /dev/null
+++ b/codego/core/environment/environment.go
@@ -0,0 +1,71 @@
+package environment
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/joho/godotenv"
+)
+
+var ENV_FILE_NAME string
+
+/* ---------------------------------------------------------------- *
+ * EXPORTS
+ * ---------------------------------------------------------------- */
+
+func ReadEnvKey(key string, optional ...string) string {
+	value, err := readEnvKey(key, optional...)
+	if err != nil {
+		log.Fatal(err)
+	}
+	return value
+}
+
+func ReadEnvKeyAllowMissing(key string, optional ...string) string {
+	value, _ := readEnvKey(key, optional...)
+	return value
+}
+
+func ReadEnvKeyDefault(key string, valueDefault string, optional ...string) string {
+	value, _ := readEnvKey(key, optional...)
+	if value == "" {
+		return valueDefault
+	}
+	return value
+}
+
+/* ---------------------------------------------------------------- *
+ * PRIVATE
+ * ---------------------------------------------------------------- */
+
+func loadEnvFile(path string) error {
+	if path == "" {
+		log.Fatal("Path name to environment file is not allowed to be empty!")
+	}
+	return godotenv.Load(path)
+}
+
+func getEnvKey(key string) string {
+	return os.Getenv(key)
+}
+
+func readEnvKey(key string, optional ...string) (string, error) {
+	var path string = ENV_FILE_NAME
+	var err error
+	var value string
+	if len(optional) > 0 {
+		path = optional[0]
+	}
+	err = loadEnvFile(path)
+	if err != nil {
+		log.Fatalf("Could not read environment file, \033[1m%s\033[0m!\n", path)
+	}
+	err = nil
+	value = getEnvKey(key)
+	if value == "" {
+		err = errors.New(fmt.Sprintf("Environment key \033[1m%s\033[0m missing or empty in environment file \033[1m%s\033[0m!", key, path))
+	}
+	return value, err
+}
diff --git a/codego/core/utils/utils.go b/codego/core/utils/utils.go
new file mode 100644
index 0000000..b4fa4cf
--- /dev/null
+++ b/codego/core/utils/utils.go
@@ -0,0 +1,84 @@
+package utils
+
+import (
+	"sort"
+	"strings"
+)
+
+/* ---------------------------------------------------------------- *
+ * EXPORTS
+ * ---------------------------------------------------------------- */
+
+func StrListContains(list []string, x string) bool {
+	for _, obj := range list {
+		if obj == x {
+			return true
+		}
+	}
+	return false
+}
+
+func Min2(x int, y int) int {
+	if x <= y {
+		return x
+	}
+	return y
+}
+
+func Max2(x int, y int) int {
+	if x >= y {
+		return x
+	}
+	return y
+}
+
+func SortStrings(list *[]string) {
+	sort.Slice(*list, func(i int, j int) bool {
+		u := strings.ToLower((*list)[i])
+		v := strings.ToLower((*list)[j])
+		cmp := strings.Compare(u, v)
+		return (cmp < 0)
+	})
+}
+
+func FilterStrings(list *[]string, f func(string) bool) []string {
+	var listFiltered = []string{}
+	for _, val := range *list {
+		if f(val) {
+			listFiltered = append(listFiltered, val)
+		}
+	}
+	return listFiltered
+}
+
+func UnionStrings2(list1 []string, list2 []string) []string {
+	var mark = make(map[string]bool)
+	for _, item := range list1 {
+		mark[item] = true
+	}
+	for _, item := range list2 {
+		mark[item] = true
+	}
+	var list = make([]string, len(mark))
+	var i int = 0
+	for item, _ := range mark {
+		list[i] = item
+		i++
+	}
+	return list
+}
+
+func UnionStringsTo(listTo *[]string, listFrom []string) {
+	var mark = make(map[string]bool)
+	for _, item := range listFrom {
+		mark[item] = true
+	}
+	for _, item := range *listTo {
+		mark[item] = false // signals suppression of duplicate addition
+	}
+	for item, isNew := range mark {
+		if isNew {
+			*listTo = append(*listTo, item)
+		}
+	}
+}
diff --git a/codego/core/utils/utils_test.go b/codego/core/utils/utils_test.go
new file mode 100644
index 0000000..59d7614
--- /dev/null
+++ b/codego/core/utils/utils_test.go
@@ -0,0 +1,57 @@
+package utils_test
+
+/* ---------------------------------------------------------------- *
+ * UNIT TESTING
+ * ---------------------------------------------------------------- */
+
+import (
+	"logik/core/utils"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+/* ---------------------------------------------------------------- *
+ * TESTCASE SortStrings
+ * ---------------------------------------------------------------- */
+
+func TestSortStrings(test *testing.T) {
+	var assert = assert.New(test)
+	var list = []string{"katze", "Hund", "baby", "Pluto", "Saturn", "Mond"}
+	utils.SortStrings(&list)
+	assert.Equal(list, []string{"baby", "Hund", "katze", "Mond", "Pluto", "Saturn"})
+}
+
+/* ---------------------------------------------------------------- *
+ * TESTCASE SortStrings
+ * ---------------------------------------------------------------- */
+
+func TestFilterStrings(test *testing.T) {
+	var assert = assert.New(test)
+	var list = []string{"abram", "aaron", "aardvark", "aarhus", "alaska", "eel", "aal"}
+	var list2 = utils.FilterStrings(&list, func(x string) bool { return strings.HasPrefix(x, "aa") })
+	assert.Equal(list2, []string{"aaron", "aardvark", "aarhus", "aal"})
+}
+
+/* ---------------------------------------------------------------- *
+ * TESTCASE UnionStrings2, UnionStringsTo
+ * ---------------------------------------------------------------- */
+
+func TestUnionStrings2(test *testing.T) {
+	var assert = assert.New(test)
+	var list1 = []string{"red", "blue", "blue", "green", "blue", "grey", "black", "green"}
+	var list2 = []string{"yellow", "orange", "lila", "red"}
+	var list = utils.UnionStrings2(list1, list2)
+	utils.SortStrings(&list)
+	assert.Equal(list, []string{"black", "blue", "green", "grey", "lila", "orange", "red", "yellow"})
+}
+
+func UnionStringsTo(test *testing.T) {
+	var assert = assert.New(test)
+	var list1 = []string{"red", "blue", "blue", "green"}
+	var list2 = []string{"yellow", "red", "black"}
+	utils.UnionStringsTo(&list1, list2)
+	utils.SortStrings(&list1)
+	assert.Equal(list1, []string{"black", "blue", "green", "red", "yellow"})
+}
diff --git a/codego/data.env b/codego/data.env
new file mode 100644
index 0000000..42460ad
--- /dev/null
+++ b/codego/data.env
@@ -0,0 +1,12 @@
+# expr = 'A0'
+# expr = '! A0'
+# expr = 'A9341'
+# expr = '!!! A84'
+# expr = '( A0 || A1 )'
+# expr = '( A0 -> A1 )'
+# expr = '( A0 && ! (0 || A8 || 1) ) -> A5'
+expr = '( A0 -> ((A0 && A3 && A4) || ! A2) )'
+# expr = '( A0 -> ((A0 && A3 && A4) || A2) )'
+# expr = '( A0 -> ((A0 && A3) || A2) )'
+# expr = '(( {G} || !{G} ) -> A5)'
+interpretation = [ "A0", "A2" ]
diff --git a/codego/go.mod b/codego/go.mod
new file mode 100644
index 0000000..394c16c
--- /dev/null
+++ b/codego/go.mod
@@ -0,0 +1,13 @@
+module logik
+
+go 1.16
+
+require (
+	github.com/antlr/antlr4/runtime/Go/antlr v0.0.0-20210506161523-0a1c3e3ce1ca
+	github.com/joho/godotenv v1.3.0
+	github.com/lithammer/dedent v1.1.0
+	// siehe https://pkg.go.dev/github.com/stretchr/testify/assert
+	// und https://github.com/stretchr/testify
+	github.com/stretchr/testify v1.7.0
+	golang.org/x/tools v0.1.0
+)
diff --git a/codego/go.sum b/codego/go.sum
new file mode 100644
index 0000000..0ff4c5a
--- /dev/null
+++ b/codego/go.sum
@@ -0,0 +1,40 @@
+github.com/antlr/antlr4/runtime/Go/antlr v0.0.0-20210506161523-0a1c3e3ce1ca h1:cZZsTEHO/8dZcxfjctHHbnEDLKdvyjUjWLNchKdgO94=
+github.com/antlr/antlr4/runtime/Go/antlr v0.0.0-20210506161523-0a1c3e3ce1ca/go.mod h1:F7bn7fEU90QkQ3tnmaTx3LTKLEDqnwWODIYppRQ5hnY=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/joho/godotenv v1.3.0 h1:Zjp+RcGpHhGlrMbJzXTrZZPrWj+1vfm90La1wgB6Bhc=
+github.com/joho/godotenv v1.3.0/go.mod h1:7hK45KPybAkOC6peb+G5yklZfMxEjkZhHbwpqxOKXbg=
+github.com/lithammer/dedent v1.1.0 h1:VNzHMVCBNG1j0fh3OrsFRkVUwStdDArbgBWoPAffktY=
+github.com/lithammer/dedent v1.1.0/go.mod h1:jrXYCQtgg0nJiN+StA2KgR7w6CiQNv9Fd/Z9BP0jIOc=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.0 h1:po9/4sTYwZU9lPhi1tOrb4hCv3qrhiQ77LZfGa2OjwY=
+golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/codego/grammars/README.md b/codego/grammars/README.md
new file mode 100644
index 0000000..c88ab85
--- /dev/null
+++ b/codego/grammars/README.md
@@ -0,0 +1,5 @@
+# ANTLR4 #
+
+Gebrauchsanleitung <https://blog.gopheracademy.com/advent-2017/parsing-with-antlr4-and-go>
+
+_Hinweis:_ In dieser Repo wurden die in der o.s. Webseite erwähnten Schritte bereits in den bash Skripten berücksichtigt.
diff --git a/codego/main.go b/codego/main.go
new file mode 100644
index 0000000..af65904
--- /dev/null
+++ b/codego/main.go
@@ -0,0 +1,95 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"logik/aussagenlogik/rekursion"
+	"logik/aussagenlogik/schema"
+	"logik/aussagenlogik/syntaxbaum"
+	env "logik/core/environment"
+	"strings"
+
+	"github.com/lithammer/dedent"
+)
+
+var DATA_ENV string = "data.env"
+
+type dataType struct {
+	expr           string
+	interpretation []string
+}
+
+type resultsType struct {
+	eval         int
+	atoms        []string
+	depth        int
+	length       int
+	nParentheses int
+}
+
+var data dataType
+
+func main() {
+	// Extrahiere Daten
+	err := getData()
+	if err != nil {
+		return
+	}
+	// Ausdruck -> Syntaxbaum
+	tree, err := schema.ParseExpr(data.expr)
+	if err != nil {
+		return
+	}
+	// Methoden ausführen:
+	results := resultsType{
+		eval:         rekursion.RekursivEval(tree, data.interpretation),
+		atoms:        rekursion.RekursivAtoms(tree),
+		depth:        rekursion.RekursivDepth(tree),
+		length:       rekursion.RekursivLength(tree),
+		nParentheses: rekursion.RekursivParentheses(tree),
+	}
+	// Resultate anzeigen:
+	displayResults(tree, results)
+}
+
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// SONSTIGE METHODEN
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+func getData() error {
+	env.ENV_FILE_NAME = DATA_ENV
+	data.expr = env.ReadEnvKey("expr")
+	s := env.ReadEnvKey("interpretation")
+	err := json.Unmarshal([]byte(s), &data.interpretation)
+	return err
+}
+
+func displayResults(tree syntaxbaum.SyntaxBaum, results resultsType) {
+	fmt.Println(fmt.Sprintf(
+		dedent.Dedent(`
+		Syntaxbaum von
+		F := %[1]s:
+
+		%[2]s
+
+		Für I = {%[3]s} und F wie oben gilt
+		eval(F, I)      = %[4]d;
+		atoms(F)        = {%[5]s};  <- *
+		depth(F)        = %[6]d;  <- *
+		length(F)       = %[7]d;  <- *
+		#parentheses(F) = %[8]d;  <- *
+
+		* noch nicht implementiert!
+		Challenge: schreibe diese Methoden! (siehe README.md)
+		`),
+		tree.Expr,
+		tree.Pretty("    "),
+		strings.Join(data.interpretation, ", "),
+		results.eval,
+		// string(results.atoms),
+		strings.Join(results.atoms, ", "),
+		results.depth,
+		results.length,
+		results.nParentheses,
+	))
+}
diff --git a/codego/run.sh b/codego/run.sh
new file mode 100755
index 0000000..5247e2f
--- /dev/null
+++ b/codego/run.sh
@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+
+################################################################################################
+# NOTE: `chmod +x run.sh` vorher ausführen, um dieses Skript benutzen zu können.
+################################################################################################
+
+################################
+# HILFSMETHODEN
+################################
+
+function call_go() {
+    go $@;
+}
+
+function check_requirements() {
+    [ -f "go.sum" ] && rm "go.sum";
+    call_go get "$( cat requirements )";
+}
+
+function precompile_grammars() {
+    local fname;
+    local name;
+    pushd grammars >> /dev/null;
+        while read fname; do
+            ( [ "$fname" == "" ] || ! [ -f "$fname" ] ) && continue;
+            name="$( echo "$fname" | sed -E "s/^(.*)\.g4$/\1/g" )";
+            echo -e "\033[92;1mANTLR4\033[0m präkompiliert Grammatik \033[1m${fname}\033[0m";
+            java -jar antlr.jar -Dlanguage=Go "$fname" -o "$name";
+        done <<< "$( ls *.g4 2> /dev/null )"
+    popd >> /dev/null
+}
+
+function compile_programme() {
+    [ -f "main" ] && rm "main";
+    echo -e "\033[92;1mGO\033[0m kompiliert \033[1mmain.go\033[0m";
+    call_go build "main.go";
+}
+
+function run_programme() {
+    echo -e "\033[92;1mGO\033[0m kompiliertes Programm wird ausgeführt";
+    ./main;
+}
+
+################################
+# HAUPTVORGÄNGE
+################################
+
+# Kann auskommentiert werden, wenn nötige Module schon installiert:
+check_requirements;
+
+# Code als Programm kompilieren und ausführen:
+precompile_grammars;
+compile_programme;
+run_programme;
diff --git a/codego/test.sh b/codego/test.sh
new file mode 100755
index 0000000..0de9535
--- /dev/null
+++ b/codego/test.sh
@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+
+################################################################################################
+# NOTE: `chmod +x test.sh` vorher ausführen, um dieses Skript benutzen zu können.
+################################################################################################
+
+################################
+# HILFSMETHODEN
+################################
+
+function call_go() {
+    go $@;
+}
+
+function check_requirements() {
+    [ -f "go.sum" ] && rm "go.sum";
+    call_go get "$( cat requirements )";
+}
+
+function run_unittests(){
+    echo -e "\033[1mUNITTESTS\033[0m\n";
+    call_go test -v -timeout 60s -count 1 -run "^Test[A-Z].*" "logik" "./...";
+}
+
+################################
+# HAUPTVORGÄNGE
+################################
+
+# Kann auskommentiert werden, wenn nötige Module schon installiert:
+check_requirements;
+
+# Code testen (unittests):
+run_unittests;