Unification (computer science) - Wikipedia
https://en.wikipedia.org/wiki/Unification_(computer_science)In logic and computer science, unification is an algorithmic process of solving equations between symbolic expressions. Depending on which expressions (also called terms) are allowed to occur in an equation set (also called unification problem), and which expressions are considered equal, several frameworks of unification are distinguished. If higher-order variables, that is, variables representing functions, ar…
Unification -- from Wolfram MathWorld
https://mathworld.wolfram.com/Unification.html17.12.2021 · Unification. Consider expressions built up from variables and constants using function symbols. If , ..., are variables and , ..., are expressions, then a set of mappings between variables and expressions is called a substitution.. If and is an expression, then is called an instance of if it is received from by simultaneously replacing all occurrences of (for ) by the …