8FUNCTIONS: iccoa - CYANA function

Synopsis: iccoa(<integer>,<integer>) = <integer>

This function returns the index of the first (if the first argument
is 1) or second (if the first argument is 2) atom that is involved
in the scalar coupling constant restraint whose index is given as
the second argument.

The scalar coupling constant restraints are indexed from 1 to ncco
in the order in which they were read from the input file(s).
