If ReturnMap is set to true, then instead of embedAsIdeal converting a module into an isomorphic ideal, this also returns the map from the module to the ring.
See also
embedAsIdeal -- embed a module as an ideal of a ring
Functions with optional argument named ReturnMap :
"embedAsIdeal(...,ReturnMap=>...)" -- see embedAsIdeal -- embed a module as an ideal of a ring
"reflexify(...,ReturnMap=>...)" -- see reflexify -- calculate the double dual of an ideal or module Hom(Hom(M, R), R)