--- layout: fc_discuss_archives title: Message 30 from Frama-C-discuss on February 2014 ---
Hi, For the attached program, all the properties were proved by Z3 but Alt-Ergo timeout/Unknown for loop invariants. If I replace UINT_MAX by a small constant, say 100, then Alt-Ergo was also able to prove if I substitute UINT_MAX by 1000. Is there any possibility to make this program verifiable with Alt-Ergo? Here is my log for Z3 and Alt-Ergo: [formal_verification]$ frama-c -wp -wp-rte -pp-annot -wp-timeout 25 -wp-proof=z3 c_nullify.c [kernel] preprocessing with "gcc -C -E -I. -dD c_nullify.c" [wp] Running WP plugin... [wp] Collecting axiomatic usage [rte] annotating function C_nullify [rte] annotating function main [wp] 13 goals scheduled [wp] [Qed] Goal typed_C_nullify_loop_inv_established : Valid [wp] [Qed] Goal typed_C_nullify_loop_assign_part1 : Valid [wp] [Z3] Goal typed_C_nullify_assert_rte_unsigned_overflow : Valid (10ms) [wp] [Z3] Goal typed_C_nullify_assert_rte_mem_access : Valid (10ms) [wp] [Z3] Goal typed_C_nullify_loop_inv_preserved : Valid (10ms) [wp] [Z3] Goal typed_C_nullify_loop_assign_part2 : Valid (10ms) [wp] [Qed] Goal typed_C_nullify_assign_part1 : Valid [wp] [Qed] Goal typed_C_nullify_loop_term_decrease : Valid [wp] [Qed] Goal typed_C_nullify_loop_term_positive : Valid [wp] [Qed] Goal typed_main_call_C_nullify_pre : Valid [wp] [Qed] Goal typed_main_call_C_nullify_pre_2 : Valid [wp] [Z3] Goal typed_C_nullify_assign_part2 : Valid [wp] [Z3] Goal typed_C_nullify_loop_assign_part3 : Valid (20ms) [formal_verification]$ frama-c -wp -wp-rte -pp-annot -wp-timeout 100 -wp-proof=alt-ergo c_nullify.c [kernel] preprocessing with "gcc -C -E -I. -dD c_nullify.c" [wp] Running WP plugin... [wp] Collecting axiomatic usage [rte] annotating function C_nullify [rte] annotating function main [wp] 13 goals scheduled [wp] [Qed] Goal typed_C_nullify_loop_inv_established : Valid [wp] [Qed] Goal typed_C_nullify_loop_assign_part1 : Valid [wp] [Alt-Ergo] Goal typed_C_nullify_assert_rte_unsigned_overflow : Valid (13) [wp] [Alt-Ergo] Goal typed_C_nullify_assert_rte_mem_access : Valid (20ms) (22) [wp] [Qed] Goal typed_C_nullify_assign_part1 : Valid [wp] [Alt-Ergo] Goal typed_C_nullify_loop_assign_part2 : Valid (20ms) (23) [wp] [Qed] Goal typed_C_nullify_loop_term_decrease : Valid [wp] [Alt-Ergo] Goal typed_C_nullify_loop_assign_part3 : Valid (Qed:4ms) (24ms) (31) [wp] [Qed] Goal typed_C_nullify_loop_term_positive : Valid [wp] [Alt-Ergo] Goal typed_C_nullify_assign_part2 : Valid (16ms) (16) [wp] [Qed] Goal typed_main_call_C_nullify_pre : Valid [wp] [Qed] Goal typed_main_call_C_nullify_pre_2 : Valid [wp] [Alt-Ergo] Goal typed_C_nullify_loop_inv_preserved : Unknown (Qed:4ms) (12s) Thanks, Dharma -------------- next part -------------- A non-text attachment was scrubbed... Name: c_nullify.c Type: text/x-csrc Size: 432 bytes Desc: c_nullify.c URL: <http://lists.gforge.inria.fr/pipermail/frama-c-discuss/attachments/20140216/50f3e3e9/attachment.c>