Thanks your code greatly helped me to get part of my results. But can you explain these two lines below? Thanks.

    while ($formula =~ s|([a-z]+)|$data{$1}//' '|e) {
        push @error, $1 unless exists $data{$1};

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In reply to Re^2: How to evaluate a mathematical formula that is stored in another file? by skooma
in thread How to evaluate a mathematical formula that is stored in another file? by skooma

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