op-sfor(fn, seq) op-sfor(fn, seq1, seq2) op-sfor(fn, seq1, seq2, seq3) apply fn to each of the superpositions in the given sequences, using a Cartesian product
-- for loop over single parameter function: fn (*) #=> |fn(> _ smerge[", "] |__self> _ |)> op-sfor( |op: fn>, split (|abc> . |de> . |xyz>)) |fn(a, b, c)> . |fn(d, e)> . |fn(x, y, z)>