Why is the following lexer grammar ambiguous for k = 2 but not for k = 3?

			

			.
			

			.
			

			.
			

			MultilineComment
			

			:        ""/*""
			

			( { LA(2) != '/' }? '*'
			

			| '
			

			'                                 { newline();            }
			

			| ""
			

			""                               { newline();            }
			

			| ~( '*' | '
			

			' | '
			

			')
			

			)*
			

			""*/""                                    { $setType(Token.SKIP); }
			

			;
			

			.
			

			.
			

			.
			

			

			ANTLR Parser Generator   Version 2.7.1   1989-2000 jGuru.com
			

			com/qsi/parser/oracle912/oracle912.g:59: warning: lexical nondeterminism upon
			

			com/qsi/parser/oracle912/oracle912.g:59:        k==1:'*'
			

			com/qsi/parser/oracle912/oracle912.g:59:        k==2:'/'
			

			com/qsi/parser/oracle912/oracle912.g:59:        between alt 1 and exit branch of block