| # "1" = 1 ⊦ pos("1".char1, '0' + '1' + '2' + '3' + '4' + '5' + '6' + '7' + ('8' + '9')) = 1 |
⊦ pos('1', '0' ' + '1' ' + '2' ' + '3' ' + '4' ' + '5' ' + '6' ' + '7' ' + '8' ' + '9' ') = 1
Used simplifier rules: ⊦ char + chars = char ' + chars;% ⊦ char + char0 = char ' + char0 ';% ⊦ # "" = 0;%str ≠ "" ⊦ # (* str) = # str.rstring + 1;