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Soundness bug on NRA formula (master + debug) without options #3484

@wintered

Description

@wintered

Consider the below trace which shows a soundness bug on a NRA formula. Z3 (master + debug) return sat, CVC4 gives unsat on bug.smt2. Feeding Z3's model to the formula yields unsat.

No related issues: I have scanned the other open "soundness bug issues". None of those has the following characteristics (1) NRA, (2) master + debug branch (3) no options.

% z3-8717c7d bug.smt2
sat
% z3debug-8d39694 bug.smt2
sat
% cvc4 bug.smt2
unsat
% cat bug.smt2
(declare-fun a () Real)  
(declare-fun b () Real)    
(declare-fun c () Real)  
(declare-fun d () Real)  
(declare-fun v () Real)   
(declare-fun e () Real)   
(declare-fun f () Real)   
(declare-fun w () Real)   
(declare-fun g () Real)   
(declare-fun h () Real)   
(declare-fun i () Real)   
(declare-fun j () Real)   
(declare-fun ep () Real)   
(declare-fun k () Real)    
(declare-fun l () Real)   
(declare-fun m () Real)   
(declare-fun n () Real)    
(declare-fun o () Real)   
(declare-fun p () Real)   
(declare-fun q () Real)   
(declare-fun r () Real)   
(declare-fun s () Real)   
(assert (not (exists ((t Real)) (= (and (and (and (= l 0.0)) 
(< (+ g (/ (/ (- a m) m) (* 2.0 (+ b r)))) h)) 
(<= a (- 6 d (- v ep )))) 
(or (= (= (<= 0.0 t) (and (<= l (* d (- v ep))) (<= 0 ep))) (= j 2.0)))))))   
(assert (not (exists ((u Real)) (=> (= 0.0 (* ( / 91 i ) q  e k)) 
(= (- c w) 2.0) (= o 2.0)))))         
(assert (= c (+ w p ) v (+ ep p)))     
(assert (= f (/ l s)))   
(check-sat)        

OS: Ubuntu 18.04
Commit: 8d39694 (master) + 8d39694 (debug)

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