AI · Theory

Unification in FOL

Theory

38/215

Unification in FOL

Unification finds substitutions that make two FOL expressions look the same. Knows(John, x) and Knows(John, Jane) unify with {x/Jane}. Occurs check stops x unifying with f(x). No unifier? fail.

It is the engine inside resolution and Prolog-style matching. Tiny pair on the board is the whole exam.

Output — idea / do / check for Unification in FOL. Fill those three in the viva.

Exam tip

One successful unify + one fail.

Example

# Unification in FOL
print("idea :", "Unification in FOL")
print("do   : one tiny example on paper")
print("check: one failure case")

Output: idea / do / check for Unification in FOL. Fill those three in the viva.

Short notes

DefSubstitution so two terms match.
Trapoccurs check.

AI · Theory

Unification in FOL

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Theory

38/215

Unification in FOL

Unification finds substitutions that make two FOL expressions look the same. Knows(John, x) and Knows(John, Jane) unify with {x/Jane}. Occurs check stops x unifying with f(x). No unifier? fail.

It is the engine inside resolution and Prolog-style matching. Tiny pair on the board is the whole exam.

Output — idea / do / check for Unification in FOL. Fill those three in the viva.

Exam tip

One successful unify + one fail.

Example

# Unification in FOL
print("idea :", "Unification in FOL")
print("do   : one tiny example on paper")
print("check: one failure case")

Output: idea / do / check for Unification in FOL. Fill those three in the viva.

Short notes

DefSubstitution so two terms match.
Trapoccurs check.

Unification in FOL

Example

Short notes

Questions

Unification in FOL

Example

Short notes

Questions