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Incorrect SAT result for NRA formula #2391

@muchang

Description

@muchang
(declare-fun a () Real)
(declare-fun b () Real)
(declare-fun c () Real)
(declare-fun d () Real)
(declare-fun e () Real)
(declare-fun f () Real)
(assert
(and
 (> 0 (- d f))
 (= d (ite (>= (/ a c) f) (+ b f) f))
 (> 0 (/ a (/ c e)))
 (or (= e 1.0) (= e 2.0))
 (> d 0)
 (= c 0)
 )
)
(check-sat)

For this formula, Z3 reports sat, while CVC4 reports unsat,.
Z3 gives the following model:

(model 
  (define-fun e () Real 1.0)
  (define-fun f () Real 2.0)
  (define-fun a () Real 1.0)
  (define-fun b () Real (- 1.0))
  (define-fun c () Real 0.0)
  (define-fun d () Real 1.0)
)

If I feed this model to the formula, Z3 reports unsat.

OS: Ubuntu 18.04
Reversion: 5de35d4

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