∇ new←lex lex∆drop key;rlex;tbl [1] ⍝⍝ Function to drop a key value pair [2] ⍎(0=1↑⍴lex)/'new←lex◊→0' [3] rlex←(⍴tbl←⊃lex[;1])⌈0,⍴key←,key [4] new←(~(rlex↑tbl)∧.=rlex[2]↑key)⌿lex ∇