Variable binding with Rational Analysis

[Troy Kelley]

This might be a dumb question, but I am going to ask it anyway because I am
stumped.  I am using ACT-R 4.0 (I know.. I know.. I will be using 5.0 some
day!! I promise!!!)

I have a TRACE from code that looks like this.

(P Begin-task
      (begin1>
           isa begin
      (problem1>
          isa problem
          firstnum 55
==>
)

When I turn on rational analysis the TRACE looks like this

(P Begin-task
      (begin1>
          isa begin
      (problem1>
          isa problem
                    firstnum =firstnum
==>
)

The question is, why when rational analysis is turned on does the trace
show the firstnum variable as a variable and not binding to the number 55?
I have a chunk, problem1, with the slot for firstnum set to 55, so that is
why the first trace shows 55, but the second trace shows only the variable
name.  Again, the only difference is that I turned on rational analysis
between the two traces.

baffled,
Troy