// This qualifier saves the day; solve constraints WITHOUT IT

qualif Zog(v:a) : (10 <= v)

bind 0 x : {v : int | true}
bind 1 y : {v : int | true}
bind 2 z : {v : int | true}

constraint:
  env [0]
  lhs {v : int | (x = 9)}
  rhs {v : int | $k0[v:=x]}
  id 1 tag []

constraint:
  env [1]
  lhs {v : int | y = 20}
  rhs {v : int | $k0[v:=y]}
  id 2 tag []

constraint:
  env [2]
  lhs {v : int | $k0[v:=z]}
  rhs {v : int | 10 <= z}
  id 3 tag []

wf:
  env [ ]
  reft {v: int | $k0}