Texas Instruments TI-83 - page 496

TI-83 Plus CATALOG, Strings, Hyperbolic Functions 493
String4Equ(
String4Equ( converts string into an equation and stores the equation to Y
n
.
string can be a string or string variable. String4Equ( is the inverse of
Equ4String(.
String4Equ(string,Y
n
)
sub(
sub( returns a string that is a subset of an existing string. string can be a
string or a string variable. begin is the position number of the first
character of the subset. length is the number of characters in the subset.
sub(string,begin,length)