Thank you for reply. Your custom procedure uses the cycle through all permutations of rows and  columns and for large m, n, m1, n1 can be computationally intensive. I meant more optimised algorithm suitable for large-sized matrices.
Nevertheless I am very much obliged to you for your fast answer.

So I have a normal vision, the font in some interface elements of Maple looks annoying. Say I would like to have bigger font in Find dialogue:

@Carl Love 

Many thanks. It's a thing I searched for. For some reasons I didn't notice Canonicalize function earlier in Lgic package.

Thank you, Lenin. Though my Spanish is poor, I fine the presention very rich and interesting. Regards.

@Joe Riel 

Joe, certainly, I know this straightforward way for debugging. But I ask about possible sophisticated way for doing tracing directly in statements sequence.

Thank you for your reply, but before posting my question I tried different encoding for an input format. Unfortunately, on my platform (Win 7 x86 Rus, Maple 17.01) UTF-8 yields unsatisfied result, whether the input file has BOM or not:

ReadLine reads all lines, but characters are completely distorted.

Is your result of reading valid?

Thank you for your reply, but before posting my question I tried different encoding for an input format. Unfortunately, on my platform (Win 7 x86 Rus, Maple 17.01) UTF-8 yields unsatisfied result, whether the input file has BOM or not:

ReadLine reads all lines, but characters are completely distorted.

Is your result of reading valid?

Yes, r. 17.01 has a bulk of impressive improvements, but the legacy crash of Classic interface during worksheet saving continues to disturb users.....

I can add, that first time faced with bugs and crushed in 16 release. All previous versions worked properly. To my mind, MapleSoft stopped to pay attention to this Interface and this is main cause of such a sad thing.