java - Reasoning about reals -

i experimenting openjml in combination z3, , i'm trying reason double or float values:

class test {    //@ requires b > 0;   void a(double b) {   }    void b() {     a(2.4);   } } 

i have found out openjml uses auflia default logic, doesn't support reals. using aufnira.

unfortunately, tool unable prove class:

→ java -jar openjml.jar -esc -prover z3_4_3 -exec ./z3 test.java -nointernalspecs -logic aufnira  test.java:8: warning: prover cannot establish assertion (precondition: test.java:3: ) in method b     a(2.4);      ^ test.java:3: warning: associated declaration: test.java:8:    //@ requires b > 0;       ^ 2 warnings 

why this?

the smt translation (used input z3) appears faulty when doubles involved. in program b below, uses doubles instead of ints, constants either call or pre-condition never translated smt.

this fault of openjml, not z3 - since z3 need of form (define-fun _jml__tmp3 () real 2345.0) work (see verbose output of program a), openjml never generates it. in general, floating point support seems buggy.

program a (with ints):

class test {     //@ requires b > 1234;     void a(int b) { }     void z() { a(2345); } } 

output (running -verbose | grep 234, search mentions of 1234 or 2345 in verbose output):

  // requires b > 1234;  pre_1 = b > 1234;     // requires b > 1234;      assume assignment pre_1_0_21___4 == b_55 > 1234; (assert (= bl_58bodybegin_2 (=> (= _jml___exception_49_49___1 null) (=> (= _jml___termination_49_49___2 0) (=> (distinct null) (=> (or (= null) (and (and (distinct null) (javasubtype (javatypeof this) t_test)) (jmlsubtype (jmltypeof this) jmlt_test))) (=> (and (<= (- 2147483648) b_55) (<= b_55 2147483647)) (=> (select _isalloc___0 this) (=> (= (select _alloc___0 this) 0) (=> (= pre_1_0_21___3 false) (=> (= pre_1_0_21___4 (> b_55 1234)) (=> pre_1_0_21___4 bl_49_afterlabel_3)))))))))))) a(2345);     // a(2345)     int _jml__tmp3 = 2345;     boolean _jml__tmp6 = _jml__tmp3 > 1234;     // a(2345)     int _jml__tmp3 = 2345     boolean _jml__tmp6 = _jml__tmp3 > 1234 (define-fun _jml__tmp3 () int 2345) (define-fun _jml__tmp6 () bool (> _jml__tmp3 1234)) 

result:

execution proof result unsat method checked ok [total 427ms]     

program b (with doubles):

class test {     //@ requires b > 1234.0;     void a(double b) { }     void z() { a(2345.0); } } 

output (running -verbose | grep 234, search mentions of 1234.0 or 2345.0 in verbose output):

// requires b > 1234.0;  pre_1 = b > 1234.0;     // requires b > 1234.0;      assume assignment pre_1_0_29___4 == b_72 > 1234.0; a(2345.0);     // a(2345.0)     double _jml__tmp3 = 2345.0;     boolean _jml__tmp6 = _jml__tmp3 > 1234.0;     // a(2345.0)     double _jml__tmp3 = 2345.0     boolean _jml__tmp6 = _jml__tmp3 > 1234.0         void z() { a(2345.0); }         //@ requires b > 1234.0; test.java:4:    a(2345.0)             value: 2345.0    === 0.0 

result:

execution proof result sat assertion not valid test.java:4: warning: prover cannot establish assertion (precondition: test.java:2: ) in method z         void z() { a(2345.0); }                     ^ test.java:2: warning: associated declaration: test.java:4:          //@ requires b > 1234.0;             ^