diff options
| -rw-r--r-- | plugins/setoid_ring/ArithRing.v | 19 | ||||
| -rw-r--r-- | test-suite/bugs/closed/6191.v | 16 |
2 files changed, 32 insertions, 3 deletions
diff --git a/plugins/setoid_ring/ArithRing.v b/plugins/setoid_ring/ArithRing.v index 447acb905..8e4d8b0d3 100644 --- a/plugins/setoid_ring/ArithRing.v +++ b/plugins/setoid_ring/ArithRing.v @@ -41,9 +41,12 @@ Ltac Ss_to_add f acc := | _ => constr:((acc + f)%nat) end. +(* For internal use only *) +Local Definition protected_to_nat := N.to_nat. + Ltac natprering := match goal with - |- context C [S ?p] => + |- context C [S ?p] => match p with O => fail 1 (* avoid replacing 1 with 1+0 ! *) | p => match isnatcst p with @@ -52,9 +55,19 @@ Ltac natprering := fold v; natprering end end - | _ => idtac + | _ => change N.to_nat with protected_to_nat + end. + +Ltac natpostring := + match goal with + | |- context [N.to_nat ?x] => + let v := eval cbv in (N.to_nat x) in + change (N.to_nat x) with v; + natpostring + | _ => change protected_to_nat with N.to_nat end. Add Ring natr : natSRth - (morphism nat_morph_N, constants [natcst], preprocess [natprering]). + (morphism nat_morph_N, constants [natcst], + preprocess [natprering], postprocess [natpostring]). diff --git a/test-suite/bugs/closed/6191.v b/test-suite/bugs/closed/6191.v new file mode 100644 index 000000000..e0d912509 --- /dev/null +++ b/test-suite/bugs/closed/6191.v @@ -0,0 +1,16 @@ +(* Check a 8.7.1 regression in ring_simplify *) + +Require Import ArithRing BinNat. +Goal forall f x, (2+x+f (N.to_nat 2)+3=4). +intros. +ring_simplify (2+x+f (N.to_nat 2)+3). +match goal with |- x + f (N.to_nat 2) + 5 = 4 => idtac end. +Abort. + +Require Import ZArithRing BinInt. +Open Scope Z_scope. +Goal forall x, (2+x+3=4). +intros. +ring_simplify (2+x+3). +match goal with |- x+5 = 4 => idtac end. +Abort. |