% sphingosine


config(sphingosine,[
        chain([
                hydroxymethyl,
                car(2,hyd&&amino),
                car(3,hyd&&hydroxyl),
                car(4,hyd)~~,
                car(5,hyd),
                num(methandiyl,12),
                methyl]),
        trans(car(3),car(6),bond(car(4),car(5)))]).