diff --git a/codego/aussagenlogik/formulae/formulae_advanced.go b/codego/aussagenlogik/formulae/formulae_advanced.go
new file mode 100644
index 0000000..d62a7fe
--- /dev/null
+++ b/codego/aussagenlogik/formulae/formulae_advanced.go
@@ -0,0 +1,23 @@
+package formulae
+
+/* ---------------------------------------------------------------- *
+ * METHOD Get Atoms
+ * ---------------------------------------------------------------- */
+
+func schemeGetAtoms(fml Formula, prevValues [](*[]Formula)) *[]Formula {
+	if fml.IsAtom() {
+		return &[]Formula{fml.Copy()}
+	} else {
+		var results = []Formula{}
+		for _, prevValue := range prevValues {
+			results = append(results, *prevValue...)
+		}
+		return &results
+	}
+}
+
+var fnGetAtoms = CreateFromSchemeFmlsValued(schemeGetAtoms)
+
+func (fml Formula) GetAtoms() []Formula {
+	return *fnGetAtoms(fml)
+}
diff --git a/codego/aussagenlogik/formulae/formulae_basic.go b/codego/aussagenlogik/formulae/formulae_basic.go
index 3085c8a..55315e6 100644
--- a/codego/aussagenlogik/formulae/formulae_basic.go
+++ b/codego/aussagenlogik/formulae/formulae_basic.go
@@ -28,18 +28,36 @@ func (fml *Formula) SetExpr(expr string) { fml.expr = expr }
 
 func (fml Formula) GetExpr() string { return fml.expr }
 
-func (fml *Formula) SetSubformulae(children [](*Formula)) {
-	fml.subformulae = children
-	fml.valence = len(children)
+func (fml *Formula) SetSubformulae(subfmls [](*Formula)) {
+	fml.subformulae = subfmls
+	fml.valence = len(subfmls)
 }
 
 func (fml Formula) GetSubFormulae() []Formula {
 	var n int = fml.valence
-	var children = make([]Formula, n)
+	var subfmls = make([]Formula, n)
 	for i, subfml := range fml.subformulae {
-		children[i] = *subfml
+		subfmls[i] = *subfml
 	}
-	return children
+	return subfmls
+}
+
+func (fml Formula) GetAllSubFormulae() []Formula {
+	var subfml = fml.GetSubFormulae()
+	var result = []Formula{fml.Copy()}
+	for _, child := range subfml {
+		result = append(result, child.GetAllSubFormulae()...)
+	}
+	return result
+}
+
+func (fml Formula) GetAllSubFormulaeStrict() []Formula {
+	var subfml = fml.GetSubFormulae()
+	var result = []Formula{}
+	for _, child := range subfml {
+		result = append(result, child.GetAllSubFormulae()...)
+	}
+	return result
 }
 
 func (fml Formula) GetChild(indexOpt ...int) Formula {
@@ -84,17 +102,27 @@ func (fml Formula) pretty(preindent string, tab string, prepend string, depth in
 	}
 }
 
+// shallow copy
+func (fml Formula) Copy() Formula {
+	return Formula{
+		expr:        fml.expr,
+		kind:        fml.kind,
+		valence:     fml.valence,
+		subformulae: fml.subformulae,
+	}
+}
+
 func (fml Formula) Deepcopy() Formula {
-	var children = make([](*Formula), len(fml.subformulae))
-	for i, child := range fml.subformulae {
-		childCopy := child.Deepcopy()
-		children[i] = &childCopy
+	var subfmls = make([](*Formula), len(fml.subformulae))
+	for i, subfml := range fml.subformulae {
+		subfmlCopy := subfml.Deepcopy()
+		subfmls[i] = &subfmlCopy
 	}
 	return Formula{
 		expr:        fml.expr,
 		kind:        fml.kind,
 		valence:     fml.valence,
-		subformulae: children,
+		subformulae: subfmls,
 	}
 }