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HELP FOR: grlimit
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CALLING SEQUENCE:  readlib ( grtools ):
                   grlimit ( expr, var, limit, fnList, valueList, LHlimit ):

      PARAMETERS:  expr      - an expression
                   var       - limiting variable
                   limit     - limiting value of var
                   fnList    - unspecified functions in expr
                   valueList - values of functions and/or their derivitives
                               w.r.t var at the limit point
                   LHlimit   - (optional) limit to number of times L'Hopital's
                               rule should be applied (default = 8)

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SYNOPSIS:

- Evaluates expr at the limit point. If indeterminate forms arise then
  L'Hopital's rule is applied (repeatedly) until the limit is resolved
  or LH_limit is exceeded. If LH_limit is exceeded the indeterminate
  portion is returned unevaluated.

- grlimit() works by substitution. It does not determine how rapidly 
  functions approach the limit point.

- Elements of valueList must consist of equations. The left-hand side of the
  equations must be a STRING containing the function at the limit point. 
  Derivitives with respect to the limiting variable by a forward quote (').
  See the example below for details.

- grlimit() first expands the expression and then evaluates term by term.
  divergent terms are then lumped together, factored into a single
  expression and that is then evaluated. This way divergent terms can
  cancel in some cases. If the final result diverges grlimit() returns
  infinity (regardless of whether it's -infinity or not).

- grlimit() is part of the grtools library. Load the library via
  readlib ( grtools ):

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EXAMPLES:

> qload ( static ):
                           Default spacetime = static
 
                           For the static spacetime:
 
                                  Coordinates
 
                             a
                           x   = [ r, theta, phi, t ]
 
                                  Line element
 
                2
        2    d r      2         2     2           2       2             2
      ds  = ------ + r   d theta   + r  sin(theta)   d phi   - h(r)  d t
             h(r)

> grcalc ( Ricciscalar ):
> Rsc := grcomponent ( Ricciscalar );

> readlib ( grtools ):
> grlimit ( Rsc, r, 0, [h(r)], [`h(0)`=1,`h(0)'`=0] );

                                 -6 h(0)''
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