Re: More /.{I->-1} craziness
- To: mathgroup at smc.vnet.net
- Subject: [mg106043] Re: More /.{I->-1} craziness
- From: dh <dh at metrohm.com>
- Date: Thu, 31 Dec 2009 03:15:11 -0500 (EST)
- References: <hhf5s3$h4o$1@smc.vnet.net>
Hi, no magic here, the pattern matcher is working on the full form, not the displayed one. You can see the full form using: "FullForm". The full form of -I is: Complex[0,-1] and that of I: Complex[0,1]. This explains why I does not match -I. I do not see a problem with E and Pi. For Infinity the full form is:DirectedInfinity[1] and for -Infinity: DirectedInfinity[-1]. Daniel On 30 Dez., 10:17, AES <sieg... at stanford.edu> wrote: > The more I play with these I->-I substitution rules, the more seemingly > wildly inconsistent results emerge. For example: > > In[1]:= -I/.I->-I > > Out[1]= -I > > In[3]:= -E/.E->-E > > Out[3]= << The Esc e e Esc symbol >> > > In[4]:= -Pi/.Pi->-Pi > > Out[4]= \[Pi] > > In[5]:= -Infinity/.Infinity->-Infinity > > Out[5]= -\[Infinity] > > (In/Out[2] is removed because it was an irrelevant cell.)