x_{1} is a rule that can be used in a Parsing Expression Grammar (PEG)

x_{1}'s first argument is the input text, its second argument is the parser's output, and its third one is the remainder of the text that the parser will process when done with this rule. Related: pegyuenzi, peglfi, pegrsto, pegrpoi, pegnpe, pegnaka, pegrcu'a, pegrke'u, pegrsu'o, pegrsu'e

- pegyuenzi
- x
_{1}is a text matching PEG rule x_{3}, resulting in output x_{2} - peglfi
- x
_{1}is a PEG rule that consumes the same input as x_{3}, but produces the output of x_{3}mapped with function x_{2} - pegnaka
- x
_{1}is a PEG negative lookahead, matching when rule x_{2}does not match - pegnpe
- x
_{1}is a PEG positive lookahead matching rule x_{2} - pegrcu'a
- x
_{1}is a PEG ordered choice rule, matching and returning the result of the leftmost possible rule in sequence x_{2} - pegrke'u
- x
_{1}is a PEG rule matching at least zero repetitions of rule x_{2}and returning a sequence of any match results - pegrpoi
- x
_{1}is a PEG rule matching what sequence of rules x_{2}matches and producing a sequence of the outputs of those rules - pegrsto
- x
_{1}is a PEG rule whose input and output is the constant x_{2} - pegrsu'e
- x
_{1}is a PEG rule matching at most one repetition of rule x_{2}and returning a sequence of any match results - pegrsu'o
- x
_{1}is a PEG rule matching at least one repetition of rule x_{2}and returning a sequence of the match results