Re: [Computer-go] Paper “Complexity of Go” by Robson

2018-06-19 Thread John Tromp
On Tue, Jun 19, 2018 at 3:55 PM, Marcel Crasmaru wrote: > "what is the computational difficulty of Capture GO?" then as far as I know > no one proved anything yet. Capture GO might be in P but to prove this > doesn't look like an easy task. I personally think it is either > > (1) in P but very

Re: [Computer-go] Paper “Complexity of Go” by Robson

2018-06-19 Thread uurtamo
Understood, and thanks. I didn't mean to throw the conversation sideways too much. Steve On Tue, Jun 19, 2018 at 7:22 AM Marcel Crasmaru wrote: > > _first capture_, no? > > I think there is some misunderstanding here as in this thread several > problems are discussed in parallel. > > If by

Re: [Computer-go] Paper “Complexity of Go” by Robson

2018-06-19 Thread Marcel Crasmaru
> _first capture_, no? I think there is some misunderstanding here as in this thread several problems are discussed in parallel. If by _first capture_ you mean to find an answer to the question "what is the computational difficulty of Capture GO?" then as far as I know no one proved anything

Re: [Computer-go] Paper “Complexity of Go” by Robson

2018-06-19 Thread uurtamo
_first capture_, no? s. On Mon, Jun 18, 2018, 6:59 PM Marcel Crasmaru wrote: > I've eventually managed to create a problem that should show a full > reduction from a Robson problem to Go - I hope is correct. > > The Problem: >

Re: [Computer-go] Paper “Complexity of Go” by Robson

2018-06-19 Thread Marcel Crasmaru
> Black can the make x false, but that allows White to make y true, after which > she can successfully escape in a ladder. I think you are right and the solution is W takes at z, B is forced to take at x, W is forced to take at y and no matter what B does next W escapes from one of the ladders

Re: [Computer-go] Paper “Complexity of Go” by Robson

2018-06-19 Thread John Tromp
On Tue, Jun 19, 2018 at 12:03 PM, Marcel Crasmaru wrote: >> White can start one ladder as a ko threat to take back the middle ko, and >> black will then take the top ko. > I claim that White cannot use the ladders as a ko thread because: > - if W plays R4 as a ko threat then B responds with S4

Re: [Computer-go] Paper “Complexity of Go” by Robson

2018-06-19 Thread Marcel Crasmaru
> White can start one ladder as a ko threat to take back the middle ko, and > black will then take the top ko. Thank you John for verifying the problem! I claim that White cannot use the ladders as a ko thread because: - if W plays R4 as a ko threat then B responds with S4 - if next W takes a

Re: [Computer-go] Paper “Complexity of Go” by Robson

2018-06-19 Thread John Tromp
On Tue, Jun 19, 2018 at 3:52 AM, Marcel Crasmaru wrote: > I've eventually managed to create a problem that should show a full > reduction from a Robson problem to Go - I hope is correct. > > The Problem: > https://drive.google.com/file/d/1tmClDIs-baXUqRC7fQ2iKzMRXoQuGmz2/view?usp=sharing > Black