function(expr, context, subIntegral) {
      if(expr.type === 'ParenthesisNode') {
        var int = subIntegral(expr.content, context, "parentheses removal");
        return int ? new ParenthesisNode(int) : null;
      }
    }
function(expr, context, subIntegral) {
      if(expr.type === 'ParenthesisNode') {
        var int = subIntegral(expr.content, context, "parentheses removal");
        return int ? new ParenthesisNode(int) : null;
      }
    }
function ( expr , context , subIntegral ) { if ( expr . type === 'ParenthesisNode' ) { var int = subIntegral ( expr . content , context , "parentheses removal" ) ; return int ? new ParenthesisNode ( int ) : null ; } }
Ignore parentheses
Ignore parentheses