string preremove fn is an evaluatable function that takes two strings as its arguments. (string preremove 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 first n tokens in STRING1. If both of these conditions are met, the function will then remove STRING2 from the beginning of STRING1 and return the resulting string. Otherwise the function will simply return STRING1. For example, (string preremove fn I like to bicycle I like ) returns to bicycle . However, (string preremove fn like to I like to bicycle ) would return like to .