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Taxonomy of Problems DDH ()


Taxonomy of Problems

 

solved

P is considered to be SOLVED if we know that it doesn't have a solution and/or know at least one solution which satisfies our needs.

0 solutions

0 solutions

exactly 1 solution

exactly 1 solution

more than 1 solution

exactly 2 solutions:::known number of solutions:::unknown number of solutions:::infinite number of solutions

unsolved

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picture of "problem about which it is impossible to find out if it can be solved or not", black background

Unsolved problems are problems for which we neither have a solution, nor know whether such solution can be found.

solvable

P is solvable if, at some point in time, a proof will be provided that solution to P can be found.

unsolvable

P is unsolvable if, at some point in time, a proof will be provided that P does not have solution.

fatal

illustration%20of%20%20%22unsolvable%20and%20undecidable%20problem%20which%20leads%20to%20madness%22%2C%20black%20background

illustration of "unsolvable and undecidable problem which leads to madness", black background

Problem P is "fatal" if no proof could ever be provided whether P is solvable or unsolvable. 

It is impossible to tell about problem if it is "fatal". That's why it is fatal ;)