Sorry, I was unclear: I know what weakly solved means. What I find curious is that the title and abstract refer to "solved", and don't mention what they actually mean. To me "solved" would suggest "strongly solved". But perhaps equating "solved" with "weakly solved" is default in this area? Still, I would like expect an abstract to say something like that explicitly.

But given the overall state of that paper I think this is a side concern at best anyway.

> But perhaps equating "solved" with "weakly solved" is default in this area?

It is the default and all that matters.

This is one of the dangers of reading papers as a non-expert. You can dismiss or be wowed by something that is totally irrelevant.

They wrote the paper very much like the Checkers paper from Science 2007.

> To me "solved" would suggest "strongly solved". But perhaps equating "solved" with "weakly solved" is default in this area?

It's the default for all reasonable games - statespace is huge (i.e. tic-tac-toe is childsplay) and simple strategies don't exist (that'd make bad human game). You can't even iterate all positions - even less prove them all for one outcome.

They wrote about this in the introduction and in the context of algorithm 2.