I want to check that the S entered something like f(7). I can sort of get it to work by using the following.
fpattern = p.product(p.literal(f
),p.number).strictOrder
countNumberUsage(this.cellContent(4,1),7)=1
However, it will also validate with f*7. I have tried using literal with parentheses:
fpattern = p.product(p.literal(f
),p.lieral((
),p.number,p.literal()
).strictOrder
But no love. Ideas?