Question

I want to the solution got back from z3 without simplification using let statements.

For example if I give the following:

(declare-const x Int)
  (elim-quantifiers (exists ((x.1 Int)) 
    (and (or (and (= (- x.1 2) 0) (<= (- x.1 9) 0)) 
             (and (or (= (- x.1 2) 0) (and (<= (- x.1 4) 0) 
                                      (and (<= (- 4 x.1) 0) 
                                           (<= (- x.1 11) 0)))) (<= (- x.1 9) 0))) (= (- (+ x.1 2) x) 0))))

I get back the solution as:

(let ((a!1 (and (or (and (<= x 4) (>= x 4)) (and (<= x 6) (>= x 6) (<= x 13)))
                (<= x 11))))
    (or (and (<= x 4) (>= x 4) (<= x 11)) a!1))

Is there a way to tell Z3 not to extract some complex expressions into a let statement ? It will be easier for me to parse the result if I get the answer flat without let statement.

Answer 1

We can set the following options to prevent the Z3 pretty printer from using lets

(set-option :pp-min-alias-size 1000000)
(set-option :pp-max-depth      1000000)

Any big number will do the trick.

We have to keep in mind that it may not be feasible to display some formulas that contain a lot of shared sub-expressions when we avoid the lets. Internally, Z3 stores the formulas as DAGs instead of Trees. If we do not use the lets, the pretty-print of such formulas may be exponentially bigger than their internal representation. So, we should not abuse the options above.