@acer Thanks for your kind reply. 

I am a beginner. I don't know too much about commands in Maple. So I only type in equations directly and press Enter. If I have 3 or functions connected with "=", after pressing Enter, it usually returns the Boolean results. So I could check my derivations (by hand) correct or not. 

Sometimes the obviously correct equations return "false". Then I type in * between specific terms, it returns "turn". Sometimes it doesn't work. Rebooting my laptop may change the value from "false" to "true". 

I do coding with C++. Same code, same computer, the code runs smoothly in the morning but breaks downs in the afternoon. I don't understand the hardcore of Maple, so it looks like some kinds of magic for me. Please find the document below.
crazy_bug.mw

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/crazy_bug.mw .

@acer Thanks, I am reading it right now. Why sometimes rebooting my laptop affects the results, with the same worksheet?