diff options
Diffstat (limited to 'Command.hs')
| -rw-r--r-- | Command.hs | 8 |
1 files changed, 4 insertions, 4 deletions
@@ -173,11 +173,11 @@ refl term = Theorem Set.empty (mkEquals term term) -subst :: Theorem -> [Object] -> Theorem +subst :: Theorem -> [Object] -> Maybe Theorem subst thm list = - let s = makeSubst list - in Theorem (Set.map (substitute s) (thmHyp thm)) - (substitute s (thmCon thm)) + do s <- makeSubst list + return (Theorem (Set.map (substitute s) (thmHyp thm)) + (substitute s (thmCon thm))) thm :: Term -> [Term] -> Theorem -> Maybe Theorem |