3 - EBNF to BNF (15 points) The following EBNF grammar defines a language of signed decimal numbers. In this notation, inline alternatives can be delimited by parentheses and separated by vertical bars, optional elements are in square brackets and a sequence in curly braces can be repeated any number of times or, if immediately followed by a + symbol, one or more times. S -> [(-|+)] {D}+ [ . {D}+ ] D -> 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 Give a regular BNF grammar for this language, i.e., one that does not use the extra notation for inline alternatives, optional elements, or repetitions.