The LR Parsing Algorithm[slide by John Werth]

A configuration of an LR parser is a pair whose first component is the stack contents and whose second component is the unexpended input:

(S₀ X₁ S₁ X₂ S₂ ... X_m S_m , a_j a_j+1 ... a_n $)

This configuration represents the right-sentential form:

(X₁ X₂ ... X_m a_j a_j+1 ... a_n)

The next move of the parser is determined by reading a_j, the current input symbol, and S_m, the state on top of the stack, and then consulting the parsing action table entry, action[ S_m , a_j ].