src/Provers/hypsubst.ML

changeset 4299 | 22596d62ce0b |

parent 4223 | f60e3d2c81d3 |

child 4466 | 305390f23734 |

--- a/src/Provers/hypsubst.ML Wed Nov 26 16:48:11 1997 +0100 +++ b/src/Provers/hypsubst.ML Wed Nov 26 16:49:07 1997 +0100 @@ -78,7 +78,7 @@ When can we safely delete the equality? Not if it equates two constants; consider 0=1. Not if it resembles x=t[x], since substitution does not eliminate x. - Not if it resembles ?x=0; another goal could instantiate ?x to Suc(i) + Not if it resembles ?x=0; consider ?x=0 ==> ?x=1 or even ?x=0 ==> P Not if it involves a variable free in the premises, but we can't check for this -- hence bnd and bound_hyp_subst_tac Prefer to eliminate Bound variables if possible.