Miscellany

<numeric>     ::= {'0'..'9'}  # limited by BASE when BASE is {2..10}
<alpha>       ::= {'A'..'Z'}  # limited by BASE when BASE is {11..36}

<number>      ::= <numeric> | <alpha>

<single>      ::= ['-']<number>+
<double>      ::= <single> '.'

<significand> ::= <digit>+['.'<digit>*]
<sign>        ::= '+' | '-'
<exponent>    ::= [<sign>]<digit>+ | <digit>*
<float>       ::= [<sign>]<significand>'E'<exponent>

<name>        ::= <graphic>+

<token>       ::= <single><space>+ | <double><space>+ | <float><space>+ | <name><space>+

<forth>       ::= <space>*[<token>]<forth>