Variable next to bracket seems not to work, e.g. x(1+x)

[q2apro]

Example x(1+x): http://fooplot.com/plot/nr9v8lks2i throws:

TypeError: vars.x is not a function

Maybe we should "scan" the string beforehand and add a * if we find a string like "variable(...)".

[dheera]

This syntax for multiplication is unsupported since x() would be interpreted as a function call.