Feature #1251

Strongest examples

On text the dictionary never trained on. The underlined token is where it fires most.

1. python 4.26
   returns the opposite of x. For example, `opposite(11)` returns `-1
2. python 4.17
   ` returns the cube of x. For example, `cubed(1)` returns `1`.
3. python 4.1
   and b. For example, `mean(1, 12)` returns `6.
4. python 4.1
   ` returns the factorial of n. For example, `fact(1)` returns `1`.
5. python 4.09
   True if x is odd. For example, `odd(11)` returns `True`.
6. python 4.04
   . For example, `lower_of(3, 11)` returns `3`.
7. python 4.03
   . For example, `max_of(7, 12)` returns `12
8. python 4.02
   b. For example, `raise_to(3, 1)` returns `3`.
9. python 3.95
   double` returns twice x. For example, `double(12)` returns `24
10. python 3.95
    numbers from 1 to n. For example, `factorial(2)` returns `2`.
11. python 3.9
    returns True if x is positive. For example, `positive(-1)` returns `False`.
12. python 3.89
    numbers from 1 to n. For example, `fact(2)` returns `2`.