peg-matching-0.1.0.0: input/peg/wiki.peg
S <- "x" S "x" / "x" -- Source: https://en.wikipedia.org/wiki/Parsing_expression_grammar#The_midpoint_problem
S <- "x" S "x" / "x" -- Source: https://en.wikipedia.org/wiki/Parsing_expression_grammar#The_midpoint_problem