Pattern test and expression sequence

*To*: mathgroup at smc.vnet.net*Subject*: [mg83122] Pattern test and expression sequence*From*: Jan Lellmann <lellmann at uni-mannheim.de>*Date*: Mon, 12 Nov 2007 05:11:00 -0500 (EST)

Hello, I want to define a pattern that accepts a sequence of expressions (of arbitrary length) that matches some condition. So as a minimalist example, if I wanted to accept all expressions with f as head and at least 2 arguments, I want to write myQ[x__] := (Print[x]; Length[{x}] > 1) f[x__?myQ] := works[x]; f[1, 2] This should print "1 2" and return "works[1,2]". But it doesn't, it just prints "1" and returns f[1,2] unevaluated. So apparenty Mathematica does not pass the complete expression sequence to myQ, but only the first element ("1"). There is a workaround using /; : f[x__] /; (myQ[x] == True) := works[x]; but it is rather ugly and cumbersome when there is more than one argument. Does anyone have an idea why Mathematica does this? Is it a bug? Or is there a (nice) workaround? Best regards, Jan