How to require integer subscripts to match a simple pattern
- To: mathgroup at smc.vnet.net
- Subject: [mg111527] How to require integer subscripts to match a simple pattern
- From: Tom D <tomdickens at att.net>
- Date: Wed, 4 Aug 2010 05:49:40 -0400 (EDT)
I am trying to create an indexed function that would be of the form M_(j,,j+1) [a,b] := func(j,a,b) , where M has the two subscripts j and j+1, i. e. I need the 2nd subscript to match only when it is 1 more than the first. I know how to do this if I made the argument 'j' a normal argument, that is, not a subscript. (Use the /; operator.) How can I do this for the subscripts? (These are propagator matrices that either go one level up, or one down, so I'll have two M's, a (j, j+1) and a (j,,j-1) version.) Thanks, Tom