Addresses issue with parens and certain operators

@kadst43 
It would make sense that it would though - right? A person should be able to be in the process of creating an equation even if they place the ending parenthesis first? We don't display the line unless the number of open and closed parentheses match and if they do something like y=x)( then the line is simply not displayed until they create an equation that is properly formatted. There's no easy way to alter which inputs a block accepts dynamically unfortunately.