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). What PL derivation rule that allows you to derive (LM)(FS) from a subproof where LM is assumed and FS is derived?