Originally Posted by zenobia43
Does the book state somewhere that each solution is unique and each step in the solution only requires logic (no guess-and-check)?
If the puzzles in the book are like the ones in the online library, there should be a way to deduce the next step without guessing.
According to the Introduction, it says:
Every puzzle in this book is solvable through logical deduction alone; trial and error and "forward guessing" are never required for a successful solve, though you are welcome to use these methods if you like!
It seems that some of the problems may have more than one solution or cannot be solved. I don't know if it happens or I miss something during solving the problems.