Perl search for same word appearing twice using { }?

[lda]

I'm trying to identify lines in a text file that have the word "light" appearing at least twice.

For example, Gen 1:3 has:
And God said, "Let there be light; and there was light.

The PCRE newbie is stumped at how to specify that with the { } syntax. I can get it to work with:
light.+light
but I want to understand how to use {2,}

I've used boost::regex, and I think the following would have worked:
(light){2,}

but this doesn't seem to work (at least for me) with PCRE.

And actually, what I'm trying to accomplish is finding a line with either "light" or "evening" appearing twice ... but not either "light" or "evening" each appearing. An example is 2 Chron 13:11 with "evening" appearing twice.

[dt192]

i used to use PERL in the olden days but now i use PHP like everyone else, i had a look around for an answer to this but couldnt find one sorry

[martinthurn]

You can not do that with the {} construct. The {} construct is used to specify multiple CONTIGUOUS occurrences of an expression. There can't be any extra stuff in between the occurrences.