| changeset 34146 | 14595e0c27e8 | 
| parent 32960 | 69916a850301 | 
| child 36361 | 1debc8e29f6a | 
--- a/src/HOL/Library/FrechetDeriv.thy Fri Dec 18 18:48:27 2009 -0800 +++ b/src/HOL/Library/FrechetDeriv.thy Fri Dec 18 19:00:11 2009 -0800 @@ -438,7 +438,7 @@ hence 2: "x + h \<noteq> 0" apply (rule contrapos_nn) apply (rule sym) - apply (erule equals_zero_I) + apply (erule minus_unique) done show "norm (?inv (x + h) - ?inv x - - (?inv x * h * ?inv x)) / norm h = norm ((?inv (x + h) - ?inv x) * h * ?inv x) / norm h"