tdpeuter/2025LogProg-project-GhentProlog
tdpeuter/2025LogProg-project-GhentProlog
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Tibo De Peuter 2025-05-05 18:04:37 +02:00
parent a937b1bc44
commit fc8b83fca3
8 changed files with 117 additions and 19 deletions
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18
src/prolog/ast/logic/Clause.kt
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@ -27,27 +27,21 @@ abstract class Clause(var head: Head, var body: Body) : Term, Resolvent {
// Only if the body can be proven, the substitutions should be returned.
// Do this in a lazy way.
val preHead = applySubstitution(head, subs)
val preGoal = applySubstitution(goal, subs)
val (headEnd, headRenaming) = numbervars(preHead, Program.variableRenamingStart, subs)
val headReverse = headRenaming.entries.associate { (a, b) -> b to a }
val (headEnd, headRenaming) = numbervars(head, Program.variableRenamingStart, subs)
Program.variableRenamingStart = headEnd
val renamedHead = applySubstitution(head, headRenaming)
unifyLazy(preGoal, renamedHead, subs).forEach { headAnswer ->
unifyLazy(goal, renamedHead, subs).forEach { headAnswer ->
headAnswer.map { headSubs ->
// If the body can be proven, yield the (combined) substitutions
val preBody = applySubstitution(body, headRenaming + headSubs) as Body
preBody.satisfy(subs).forEach { bodyAnswer ->
bodyAnswer.fold(
onSuccess = { bodySubs ->
var result = (headSubs + bodySubs)
.mapKeys { applySubstitution(it.key, headReverse) }
.mapValues { applySubstitution(it.value, headReverse) }
result = result.map { it.key to applySubstitution(it.value, result) }
.toMap()
.filterNot { it.key in headRenaming.keys && !occurs(it.key as Variable, goal, emptyMap())}
val newSubs = headSubs + bodySubs
val result = newSubs
.mapValues { applySubstitution(it.value, newSubs) }
.filter { it.key !is AnonymousVariable && occurs(it.key as Variable, goal, emptyMap()) }
yield(Result.success(result))
},
onFailure = { error ->