Notes

The modal indexes are allowed to be only strings containing letters - at the moment - (any other thing will result in a parsing error).

The binding order "~" >> "/\" >> "\/" >> "<-" = "->" = "<->" is not set yet.

Eronated tests (string-index) formulae: 2,3,7,8,9,10

integer

bit-string 15

Good tests (string-index) formulae: 0,1,2,4,5,6,11,12

integer 13, 14, 15

bit-string 14