Newest commit breaks "Letter + number "words" (e.g., F1 → F2)"

[marcusfschmidt]

The newest merge seems to break the functionality of the letter + number words. I discovered this while trying to add cos and sin, whereupon it would simply jump to the argument in the parenthesis and increment the number.

I tried out the letter + number words and realized it would keep incrementing further than 9, which does not seem like the intended functionality.

Downgraded to 4dd3882 - here it works again, and I can also toggle between e.g. cos(3t) and sin(3t).

[nat-418]

Thanks for the report, I will look into this.