diff options
Diffstat (limited to 'src/disjoint.sml')
| -rw-r--r-- | src/disjoint.sml | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/disjoint.sml b/src/disjoint.sml index 503544af..5cc9d1fb 100644 --- a/src/disjoint.sml +++ b/src/disjoint.sml @@ -254,7 +254,8 @@ and prove env denv (c1, c2, loc) = val hasUnknown = List.exists (fn Unknown _ => true | _ => false) val unUnknown = List.mapPartial (fn Unknown _ => NONE | Piece p => SOME p) in - if hasUnknown ps1 orelse hasUnknown ps2 then + if (hasUnknown ps1 andalso not (List.null ps2)) + orelse (hasUnknown ps2 andalso not (List.null ps1)) then [(loc, env, denv, c1, c2)] else let |