I'll go along with most of that except

If you use an empty pattern in the substitution, Perl will do the right thing. Another five characters.

Without the negative lookahead, the regex will produce a very high proportion of invalid expressions because it will insert an operator at the very end of the string: 

9+8*7*6*54/3-2/1-
-9-8-7*6+5/43/2+1
987+6/54321
98/7-6+5-4/321+
9*8/7/6/54-3/2-1
9/876*543/21
-9*8/76543*2-1-
-987/65-432+1*
9*8+7+65*432*1-
9876/5*43+21
9876-54321*
987/6-5-4/3-21/
9-8+7*65432+1
98765+432*1+
-9*8-7*65432-1+
9+87*6543*21
9-87*65*4-3-2*1
-987654-321+
98*76/54*32*1-
-9-876/5-432*1*
-987*654+321
9/87+6543*21
98-7654/3+21
-98*7-6-5*4321
98+7+6/5+4*3+2-1
-98+76+54*3/2+1/
9876543/21
-9-8+76-54321*

[download]

Not always, and so it can be expected to still produce occasional correct answers, but it will take much longer and somehow offends my sensibilities :)

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

In reply to Re^3: Happy 2006 (Golf) by BrowserUk
in thread Happy 2006 by Perl Mouse

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