Solving a logic puzzle using Prolog

Question

The criminal is one of A, B, C and D.

A says: \"It\'s not me\"
B says: \"It\'s D\"
C says: \"It\'s B\"
D says: \"It\'s not me\"

Answer 1

One-liner solution

?- member(K,[a,b,c,d]),(K\=a->A=1;A=0),(K=d->B=1;B=0),(K=b->C=1;C=0),(K\=d->D=1;D=0),A+B+C+D=:=1.
K = a,
A = 0,
B = 0,
C = 0,
D = 1 ;
false.