Normally, a function is entered in the form
function(parameter, parameter). However, Equals can also recognize functions as simply
function. In this case, the opening and closing parentheses are implicitly added. This is only useful when entering constants, since these are the only functions which do not accept parameters. The upshot of this is that you can pass the string
π + e and it will be correctly processed as if you had passed
π() + e().
If you attempt to use this with other functions, an error will occur and evaluation will fail. This makes sense since (for example)
sin() cannot be evaluated; the
sin function requires a parameter.