Answer the following question with one of the following abbreviations for the PL derivation rules: ^E, ^I, ->E, ->I, ~I, ~E, vI, vE, <->I, <->E, R, IMP, DEM, HS, DN. (NOTE: Type the abbreviation exactly as it appears (with no spaces) OR copy-and-paste it from the question). WhatPL derivation rule that allows you to derive(LM)(FS)

(LM)(FS)

froma subproof whereLM

LM

is assumed andFS

FS

is derived?