Thanks for the reply, Rhodium.
SWIM can visualize and draw most (if not all) tryptamines and phenethylamines, and most of the PEA-intermediates - but GHB and friends, hasn't been just as easy figuring out, as the others.
SWIM is learning day by day.
Anyway, SWIM was assuming, that 4-Methyl-gamma-Butyrolactone equaled para-Methyl-gamma-Butyrolactone, like pMA = 4-MA...
Thanks for the clarification, although this one still confuses SWIM.
SWIM will read Vogel and other literature, UTFSE, and keep asking newbee questions!