E1:     C1 CALL pred shallow.main/2-0 (cc_multi) shallow.m:24
mdb> echo on
Command echo enabled.
mdb> context before
Contexts will be printed before, on the same line.
mdb> context
Contexts are printed before, on the same line.
mdb> step
      E2:     C2 CALL shallow_helper_1.m:17 pred shallow_helper_1.safe/1-0 (semidet)
mdb> print *
       HeadVar__1             	[1, 2, 3, 4, 5]
mdb> stack
   0       pred shallow_helper_1.safe/1-0 (semidet) (shallow_helper_1.m:17)
   1       pred shallow.queen/2-0 (nondet)
   2       pred shallow.main/2-0 (cc_multi) (shallow.m:25)
mdb> c -S
[1, 3, 5, 2, 4]