string postremove fn is an evaluatable function that takes two strings as its arguments. (string postremove fn STRING1 STRING2) tests for two conditions: (1) the length of STRING1 is longer than the length of STRING2. (2) the n tokens in STRING2 exactly match the last n tokens in STRING1. If both of these conditions are met, the function will then remove STRING2 from the end of STRING1 and return the resulting string. Otherwise the function will simply return STRING1. For example, (string postremove fn I like to bicycle to bicycle ) returns I like . However, (string postremove fn like to I like to bicycle ) would return like to .