#### 7.50 bug in dsolve in Maple V.5 (20.4.98)

There appears to be a new bug in Release 5 that prevents Maple from solving
odes with conditions if the unknown function is an indexed name rather than a
symbol.

Release 4 could do this. I think that the problem is in the library procedure
``dsolve/IC/format``

. The worksheet

http://www.maths.qmw.ac.uk/~fjw/public_maple/dsolve_IC_format.mws

proposes a ﬁx and gives a test example, although I have not investigated this very deeply nor
tested it very thoroughly. I would be interested to hear of examples where my ﬁx also fails.
The problem is essentially that this procedure tries to treat functions, e.g. `y(0)`

, and
derivatives, e.g. `D(y)(0)`

, the same, in a way that happens to work if y is a symbol but not if
it is indexed, e.g. `z[1]`

.

(The indexed notation `z[i]`

is pleasanter than the symbol notation `z.i`

when dealing with a
system of odes.)

Yes, it was in ``dsolve/IC/format``

. This problem was detected in January, and posted in
`sci.math.symbolic`

. A ﬁx to this is also provided inside the `ODEtools`

package available at
http://lie.uwaterloo.ca/odetools.html.