known, but inferrable, yet not inferred, property not given as precodition to provers
ID0002330: This issue was created automatically from Mantis Issue 2330. Further discussion may take place here.
| Id | Project | Category | View | Due Date | Updated |
|---|---|---|---|---|---|
| ID0002330 | Frama-C | Plug-in > wp | public | 2017-10-26 | 2020-02-17 |
| Reporter | Jochen | Assigned To | correnson | Resolution | fixed |
| Priority | normal | Severity | minor | Reproducibility | always |
| Platform | Phosphorus-20170501 | OS | - | OS Version | xubuntu 17.04 |
| Product Version | - | Target Version | - | Fixed in Version | Frama-C 20-Calcium |
Description :
Running "frama-c -wp foo.c -wp-out wp-out -wp-prop=D" on the attached program fails to prove the property D, although it follows immediately from A and C. A look at the generated file "foo_assert_D_Alt-Ergo.mlw" reveals that the condition "y<=15" from C is not given to Alt-Ergo, while "0<=y" is. If the former is inserted into the mlw file, Alt-Ergo proves the goal without problems. Probably, "y<=15" is considered a trivial consequence of "y==(x&0xf)" by Qed; however, it shouldn't, since (e.g.) Alt-Ergo is unable to to infer this: goal C cannot be proven by Alt-Ergo.
Steps To Reproduce :
Name translation c -> mlw for convenience:
x -> i y -> x z -> x_1