Searching for substrings ======================== Searching for substrings is done with `index': index(STRING, SUBSTRING) which expands to the index of the first occurrence of SUBSTRING in STRING. The first character in STRING has index 0. If SUBSTRING does not occur in STRING, `index' expands to `-1'. index(`gnus, gnats, and armadillos', `nat') =>7 index(`gnus, gnats, and armadillos', `dag') =>-1