Using perl -MO=Deparse may shed some light on some of this weirdness, although I have no idea why on Earth anyone would implement 'inf' the way it works on my box.

perl -MO=Deparse -e 'print $n[inf]'
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prints

print $n[9**9**9];
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as does

perl -MO=Deparse -e 'print $n["inf"]'
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On the other hand,

perl -MO=Deparse -e 'print $n[-inf]'
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prints

print $n[-'inf'];
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perl -MO=Deparse -e 'print "", inf==0 ? "a" : "b", 'inf'==0 ? "c" : "d
+", -inf==0 ? "e" : "f"'
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prints

print '', 'inf' == 0 ? 'a' : 'b', 'inf' == 0 ? 'c' : 'd', -'inf' == 0 
+? 'e' : 'f';
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As nearly as I can tell at the moment, inf is only equivalent 9**9**9 if it is used by itself as a subscript; it is taken as a bareword in a simple assignment, so

perl -MO=Deparse -e '$n[inf], $n[1+inf], $n[-inf] = inf'
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prints

$n[9**9**9], $n[1 + 'inf'], $n[-'inf'] = 'inf';
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My perl -v shows,

This is perl, v5.8.8 built for i486-linux-gnu-thread-multi
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Does anyone know why? - quester