Handle bracket matching on the left hand side

[sanity]

Let's say we define a function:

dog cat = fight

Now we type:

(dog) cat

This should match the left side of the function, but it doesn't.

This problem occurred here:

markup = 30%
markup of 78

The incorrect result was:

(30 %) of 78

The "X of Y%" function defined in bootstrap.txt didn't match because the brackets had been inserted automatically.