I don't think is fully logical. I used the 'upper left' hint and I made some guesses to solve it.

I did it logically with temps, didn't see hint.

That actually refers to what part this is in the larger picture being made.

All logical, very nice puzzle !

Super tough but logical! Thanks :)

You sure it's logical? Got stuck in the first five minutes, then had to "cheat" with temps and checking the other pieces in the big picture.

I also found it completely logical and extremely difficult. Well worth doing if you have the time to sweat it out.

Please some help?

''and then we said, it's logical''.

It is completely logical ;)

if you need some help to get started:
c1: r1, r3-5, r9, r11, r13-18.

WOW - hard work, but it works, it's logical.
BTW using temps isn't cheating!
Very challenging and good!

Fully logical. Can be solved without hints. Thank you for the puzzle.