_expr</a> <span class="xref-unresolved">Bap</span>.Std.Var.Map.t</span> <span class="arrow">&#45;&gt;</span></span>
  <span>string <span class="arrow">&#45;&gt;</span></span>
  <span><span>( <span><span class="xref-unresolved">Bap</span>.Std.Var.t <span class="arrow">&#45;&gt;</span></span> string )</span> <span class="arrow">&#45;&gt;</span></span>
  <span><a href="../Constraint/index.html#type-z3_expr">Constr.z3_expr</a> option</span></span></code></div><div class="spec-doc"><p>Looks up a Z3 variable's na