HW3: Unification of procedures

[avikalpg]

Since we are comparing the strings of procedures, hence 2 procedures that are defined using exactly the same letters will be shown to be equal but those doing the same job will be called unequal if they use different variable names.

The actual implementation will show that 2 functions defined in the same text but not unified as unequal (as they are not in the same equivalence class)