admissible chains and i-boxes

Admissible chain and i-box construction in type A_n

Build the admissible chain, the double string, and the opening of the double inductive weave.

Input

Type A rank n Length r

Randomly chooses the underlying Δ, LR sequence, and admissible chain in type A_n.

Expression sequence 𝐢 Expression sequence Δ LR sequence

Entries may be separated by spaces, commas, or line breaks. The initial envelope is c = #{L entries} + 1.