Hi,
Thank you for the posting. I really enjoy the reading. I do have a question about the proof of Conway's algorithm. Professor Nishiyama uses theorem X, Y, Z from Stanely Colings (1982) for the proof. But I couldn't find a copy of this 1982 article and it would be great if you can post the proof of the 3 theorems from Collings.

## the proof of Collings's theorems

Hi,

Thank you for the posting. I really enjoy the reading. I do have a question about the proof of Conway's algorithm. Professor Nishiyama uses theorem X, Y, Z from Stanely Colings (1982) for the proof. But I couldn't find a copy of this 1982 article and it would be great if you can post the proof of the 3 theorems from Collings.

Thank you.