a non-empty sequence of decimal digits

$\boxml{0},\twoldots,\boxml{9}$ and the underscore (\wildpat) that

neither starts nor ends with an underscore.

An\index{6.2} {\sl integer constant} is an optional negation symbol

An\index{6.2} {\sl integer constant (in decimal notation)} is an optional negation symbol

(\tttilde) followed by a positive integer constant. }{%

An\index{6.2} {\sl integer constant (in

decimal notation)} is an optional negation symbol (\tttilde)

hexadecimal notation)} is an optional negation symbol

followed by\boxml{0x} followed by a non-empty sequence of

hexadecimal digits$\boxml{0},\twoldots,\boxml{9}$

and$\boxml{a},\twoldots,\boxml{f}$\ADD{, and the underscore thatdoes not

end with an underscore}.

and$\boxml{a},\twoldots,\boxml{f}$\ADD{ and the underscore thatneither starts nor ends

ends with an underscore}.

($\boxml{A},\twoldots,\boxml{F}$

may be used as alternatives for$\boxml{a},\twoldots,\boxml{f}$.)

\ADD{

An {\sl integer constant (in binary notation)} is an optional negation

symbol followed by a non-empty sequence of binary digits\boxml{0},\boxml{1},

and the underscore thatdoes not end with an underscore.

symbol followed by\boxml{0b} followed bya non-empty sequence of binary digits$\boxml{0},\boxml{1}$

and the underscore thatneither starts nor ends with an underscore.

}

A {\sl word constant (in decimal notation)} is\boxml{0w} followed

by a non-empty sequence of decimal digits\ADD{ and the underscore thatdoes not

end with an underscore}.

by a non-empty sequence of decimal digits\ADD{ and the underscore thatneither starts nor

ends with an underscore}.

A {\sl word constant

(in hexadecimal notation)} is\boxml{0wx} followed by a non-empty

sequence of hexadecimal digits\ADD{ and the underscore thatdoes not

end with an underscore}.

sequence of hexadecimal digits\ADD{ and the underscore thatneither starts nor

ends with an underscore}.

\ADD{A word constant (in binary notation) is\boxml{0wb} followed by a non-empty

sequence of binary digits\boxml{0},\boxml{1},and the underscorenot ending with

sequence of binary digits and the underscorethat neither starts nor ends with

an underscore.}

A {\sl real constant} is an integer constant in decimal notation,