public override bool Evaluate(RuntimeValues runtimeEnv)
 {
     if (_or)
     {
         return(_left.Evaluate(runtimeEnv) || _right.Evaluate(runtimeEnv));
     }
     else
     {
         return(_left.Evaluate(runtimeEnv) && _right.Evaluate(runtimeEnv));
     }
 }
 public override bool Evaluate(RuntimeValues runtimeEnv)
 {
     return(!expr.Evaluate(runtimeEnv));
 }