[FOM] 2,3 Turing machine proof controversy

[Vaughan Pratt]

Vaughan Pratt wrote:
>  Let W (for "whitelocked") be the 
> subclass of T constrained to hold the average head position constant 
> (equivalently the heads must move in opposite directions) when both 
> heads are scanning a white cell.

T should have been I.

I'll be traveling the next two weeks so may be a bit slow responding to 
emails.

Vaughan Pratt