Prolog Comparison Returns False

0
votes

I apologise upfront as I suspect this is a basic prolog question. I have the following knowledge base to define a family tree

male(james1).
male(james2).
male(charles1).
male(charles2).
male(george1).
female(catherine).
female(elizabeth).
female(sophia).
parent(charles1, james1).
parent(elizabeth, james1).
parent(charles2, charles1).
parent(catherine, charles1).
parent(james2, charles1).
parent(sophia, elizabeth).
parent(george1, sophia).

I wrote the following query parent(charles1,james1) == parent(elizabeth,james1).

I expected true as james1 is the parent of elizabeth and charles1. Both queries return true so why does the == return false?

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