quads: MALFORMED tests/issues/test1078.pl:12
   ?- X=1.
   not an answer: 1=X
quads: MALFORMED tests/issues/test1078.pl:15
   ?- Y=1.
   not an answer: Y=2
quads: MALFORMED tests/issues/test1078.pl:18
   ?- Z=f(W),W=1.
   not an answer: Z=f(W)
quads: BAD_ID tests/issues/test1078.pl:21
   ?- true.
   identifier is not ground
quads: 6 run, 2 passed, 4 failed.