@Carl Love 

You can find the .pdf of the whole worksheet HERE

Also the Mathematica code can be found HERE

@ 

Thank you very much!

I will try to make it work!

@Joe Riel 

Thank you for your answer!

The problem isn't only the 20, but all the numbers (0.00 is not recognized equal with 0, etc..)! Is any way to use verify for that for all the numbers?

i.e.

for i from 0 to 30 by 0.05 do
u(i,i+0.05);
od;

one of the outcomes is u(20.00,20.05) (or any numer) and Maple does not recognize that this is equal with u(20,20.05).