Negation as failure in Prolog is a procedural behavior?

Question

I have a little question about the negation as failure in Prolog language:

This is a question more theoretical than practical because I have clear h

Answer 1

I disagree with 'limitations of the logic'.

The same would be

likes(mary,X) :- not(snake(X)) , animal(X).

Because Prolog uses a depth-first-search some things can be expressed in an shorter way that then depends on the depth-first-search backtracking algorithm.

x :- a, !, b.
x :- c.
x :- d.

is the same as

x :- a, b.
x :- not(a), c.
x :- not(a), d.