# Given sum of sequences, choose two sequence elements and make other sequence zero with making some sequence vanishes and others keep untouched

Slightly modified from my previous question Making function for a given input of sum of sequences, choose two sequence \$ a_i, b_j\$ and substitute all other sequence zero

At this time I want to make among many sequences, just pick two sequences and other kept untouched.

For example

input = a1a2b1b2c2c3 + 100a1b2d1 + a1c2b2d3 + a1a2 + a3c1c2 + a3c1 + d1a2 + d2c1

If I choose two sequences $$a$$ and $$b$$, and pick its elements as $$a_1, b_1$$ then I want to put all other sequences of $$a,b$$ are zero with additionally make all $$c$$ vanishes but $$d$$ kept remained.

For example if my input is something like $$f[input, a1,c1]$$ then $$a2=a3=0, c2=c3=0$$ with vanishing sequence of b1,b2,.. but kept $$d1,d2\neq 0$$.

Maybe to be more specified, I want to make function which have [input, sequnece1_{i}, sequence2_{j}, sequence3], where sequence1, sequuence2, have non-zero element for i,j respectively, and the other elements of sequence 3, vanishing for given a,b,c,d,e.,,, sequences.