Less than

is a comparison function which tests whether the left argument is tolerantly less than and not equal to the right argument, returning 1 if this is the case and 0 otherwise. It is the negation of Greater than or Equal to.

Less than is also notable as a Boolean function, in which case it returns 1 only if the left argument is 0 and the right argument is 1 (the same as Residue). In particular, Less-than Scan on a Boolean vector returns a vector which indicates the position of the first 1 in the argument, if any:

Boolean function
When used as a Boolean function (that is, with argument consisting entirely of 0s and 1s), it represents converse nonimplication: In the context of logic, it can be read as isn't, as opposed to.

Documentation

 * Dyalog
 * APLX
 * J Dictionary, NuVoc