--- layout: fc_discuss_archives title: Message 12 from Frama-C-discuss on September 2020 ---
I have been attempting to generate Coq code using ACSL specifications in order to manually prove anything that cannot be handled by Alt-Ergo or Z3. An issue that occurs quite often is that in the auto-generated Coq code, I get the following error: Goal let x := ((L_int_pow 2%Z 4%Z))%Z in forall (t_1 t : array Z), forall (t_3 t_2 : farray addr Z), forall (a : addr), ((0 < x)%Z) -> ((((region ((base a))%Z)) <= 0)%Z) -> ((x <= 2147483647)%Z) -> ((linked t)) -> ((sconst t_2)) -> ((P_valid_read_string t_1 t_3 ((shift_sint8 ((global (Str_39)%Z)) 0%Z)))) -> ((P_valid_read_string t_1 t_3 ((shift_sint8 ((global (Str_40)%Z)) 0%Z)))) -> ((is_finite_f64 ( *1 / 5* )%R%R)). Where the bold red "1 / 5" throws the issue of being type "real" while it is expected to have type "f64". This is a simple enough issue to fix by manually casting "to_f64(1 / 5)" and then solving in Coq, but this code is auto-generated each time. This means anything I put within the actual proof will remain, but my typecast will not. I have not been able to determine a way to trace this code to anywhere in the original C code, otherwise I would try changing the source. Any suggestions are welcome. Best, Joshua Miller -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.gforge.inria.fr/pipermail/frama-c-discuss/attachments/20200925/54ac8e33/attachment.html>