My understanding is that:

$1 $2 $3 supposed to refer to the 3 elements on the right of the production.

While $$ refer to the LHS of the production. But in this production, there're only 3 elements on the right hand side, and I don't see what $4 refers to...

In reply to Re^2: Where does $4 come from here? by PerlOnTheWay
in thread Where does $4 come from here? by PerlOnTheWay

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