- (substring=? STRING1 STRING2 [START1 [START2 [LENGTH]]]) procedure
- (substring-ci=? STRING1 STRING2 [START1 [START2 [LENGTH]]]) procedure
Returns #t if the strings STRING1 and STRING2 are equal, or #f otherwise. The comparison starts at the positions START1 and START2 (which default to 0), comparing LENGTH characters (which defaults to the minimum of the remaining length of both strings).