Bottom Up Parse of a Regular Expression Grammar 1) use this regular expression grammar. E => T | E or T T => F | T F F => sym | F * | (E) 2) I have constructed a PDA that accepts legal regular expressions by parsing from the bottom up. 3) Trace the parsing of the regular expression x(xy*|z) showing snapshots of the stack. Show a separate snapshot of the stack just before each RHS is popped off it. Hint: pda are non-deterministic so it is hard to guess what they should do to accept. So use your human abilities to make a parse tree, and then use the parse tree to guide you as you trace the behavior of the PDA.