> Even a P=NP result doesn't tell us that NP problems have efficient solutions.
Yes it does. That is literally exactly what it means. The class P is the class of problems which are considered theoretically "tractable"/"efficiently solvable"/"feasibly solvable" (Cobham-Edmonds thesis). Hence, if NP=P, then that same definition extends to all problems in NP.
Yes it does. That is literally exactly what it means. The class P is the class of problems which are considered theoretically "tractable"/"efficiently solvable"/"feasibly solvable" (Cobham-Edmonds thesis). Hence, if NP=P, then that same definition extends to all problems in NP.