function example does not give enough examples

[guigui0246]

These should also work because they follow the rules "any letters of 'function' in order" but all exmaples starts with f

n add(a, b) => a + b!
cn multiply(a, b) => a * b!
nn subtract(a, b) => a - b!
no divide(a, b) => a / b!

[Ionathan-Hope]

i fixed it close it

[guigui0246]

@Ionathan-Hope What PR ?

[guigui0246]

If it's #713 then no because I'm not ok with everything there