i
unsolved DDH ()


unsolved

picture%20of%20%22problem%20about%20which%20it%20is%20impossible%20to%20find%20out%20if%20it%20can%20be%20solved%20or%20not%22%2C%20black%20background

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 ;)