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RE: why Pi is not recognized as a positive number?

• To: mathgroup at smc.vnet.net
• Subject: [mg45364] RE: [mg45360] why Pi is not recognized as a positive number?
• From: "David Park" <djmp at earthlink.net>
• Date: Sat, 3 Jan 2004 01:35:07 -0500 (EST)
• Sender: owner-wri-mathgroup at wolfram.com

Peter,

x_Positive is the pattern for an expression that has the Head Positive - not
what your want. You want...

f[x_?Positive] := x + 1

f[Pi]
1 + Pi

David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/


From: Pedro L [mailto:pedrito6 at softhome.net]
To: mathgroup at smc.vnet.net

  I wanted to define a function for the positive numbers. But I discovered
  something "strange" with Mathematica.

  Could you help me with this?

  Thanks in advance.

  Peter L  (Spain)



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