c1 := 'abcde' ----> 'abcde'
c2 := 'aeuoi' ----> 'aeiou'
c1 ++ c2 ----> 'abcdeiou'
c1 -- c2 ----> 'bcd'
c1 ** c2 ----> 'ae'
Run-time error 104 at line 14 in expr34.icn
cset expected
offending value: []