Configurations in LR parser

Stack: S₀ X ₁ S₁ X₂ .X _m S_m Input: a_i a_i+1 .a_n $

. If action[S_m ,a_i ] = shift S Then the configuration becomes

Stack : S₀ X₁ S₁ ..X_m S_m a _i S Input : a_i+1 .a_n $

. If action[S _m ,a_i ] = reduce A ß Then the configuration becomes

Stack : S₀ X ₁ S₁ .X _m-r S_m-r AS Input : a_i a_i+1 .a_n $

Where r = | ß | and S = goto[S _m-r ,A]

. If action[S_m ,a_i ] = accept

Then parsing is completed. HALT

. If action[S_m ,a_i ] = error

Then invoke error recovery routine.