Consider following example:
The notes of the first chord are modified in order to correspond to the pitches of the second chord, but octaving is permitted: the high C stays C, the low A# stays A# (as these pitch classes are present in the second chord).
Is it possible to obtain the same operation, but only the exact pitches of the second chord are permetted (so no octaving)? The high C would therefore become an A#, and the low A# a C.
Is this related to the 3rd input: mod(ulo)?