Uncaught Mercury exception:
Software Error: detected infinite recursion in pred tc_loop.tc/2
Stack dump follows:
   0       pred exception.throw/1-0 (erroneous) (exception.m:NNNN)
   1       pred require.error/1-0 (erroneous) (require.m:NNNN)
   2    3* pred tc_loop.tc/2-0 (nondet) (tc_loop.m:26 and others)
   5       pred std_util.builtin_aggregate/4-6 (det) (std_util.m:NNNN)
   6       pred std_util.builtin_solutions/2-1 (det) (std_util.m:NNNN)
   7       pred std_util.solutions/2-1 (det) (std_util.m:NNNN)
   8       pred tc_loop.main/2-0 (det) (tc_loop.m:14)