127 lines
2.7 KiB
Go
127 lines
2.7 KiB
Go
package formulae
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/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *
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* CONSTANTS
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* ---------------------------------------------------------------- */
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var Tautology = Formula{
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kind: "taut",
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expr: "1",
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valence: 0,
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subformulae: [](*Formula){},
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}
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var Contradiction = Formula{
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kind: "contradiction",
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expr: "0",
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valence: 0,
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subformulae: [](*Formula){},
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}
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/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *
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* METHODS: Constructions
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* ---------------------------------------------------------------- */
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func Atom(expr string) Formula {
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return Formula{
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kind: "atom",
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expr: expr,
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valence: 0,
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subformulae: [](*Formula){},
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}
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}
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func NegatedAtom(expr string) Formula {
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return Negation(Atom(expr))
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}
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func Generic(expr string) Formula {
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return Formula{
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kind: "generic",
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expr: expr,
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valence: 0,
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subformulae: [](*Formula){},
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}
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}
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func Negation(fml Formula) Formula {
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return Formula{
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kind: "not",
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expr: "!" + " " + fml.expr,
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valence: 1,
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subformulae: [](*Formula){&fml},
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}
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}
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func Conjunction2(fml1 Formula, fml2 Formula) Formula {
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return Formula{
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kind: "and2",
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expr: "(" + fml1.expr + " && " + fml2.expr + ")",
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valence: 2,
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subformulae: [](*Formula){&fml1, &fml2},
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}
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}
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func Conjunction(fmls []Formula) Formula {
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var expr string = ""
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var children = make([](*Formula), len(fmls))
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for i, fml := range fmls {
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if i > 0 {
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expr += " && "
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}
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expr += fml.expr
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children[i] = &fml
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}
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return Formula{
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kind: "and",
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expr: "(" + expr + ")",
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valence: len(children),
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subformulae: children,
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}
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}
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func Disjunction2(fml1 Formula, fml2 Formula) Formula {
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return Formula{
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kind: "or2",
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expr: "(" + fml1.expr + " || " + fml2.expr + ")",
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valence: 2,
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subformulae: [](*Formula){&fml1, &fml2},
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}
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}
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func Disjunction(fmls []Formula) Formula {
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var expr string = ""
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var children = make([](*Formula), len(fmls))
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for i, fml := range fmls {
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if i > 0 {
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expr += " || "
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}
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expr += fml.expr
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children[i] = &fml
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}
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return Formula{
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kind: "or",
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expr: "(" + expr + ")",
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valence: len(children),
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subformulae: children,
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}
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}
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func Implies(fml1 Formula, fml2 Formula) Formula {
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return Formula{
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kind: "implies",
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expr: "(" + fml1.expr + " -> " + fml2.expr + ")",
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valence: 2,
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subformulae: [](*Formula){&fml1, &fml2},
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}
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}
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func DoubleImplication(fml1 Formula, fml2 Formula) Formula {
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return Formula{
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kind: "iff",
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expr: "(" + fml1.expr + " <-> " + fml2.expr + ")",
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valence: 2,
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subformulae: [](*Formula){&fml1, &fml2},
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}
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}
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