** 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:

* (S _{0} X_{1} S_{1} X_{2} S_{2} ... X_{m} S_{m} , a_{j} a_{j+1} ... a_{n} $)*

This configuration represents the right-sentential form:

* (X _{1} X_{2} ... 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