denis_berthier wrote:I don't know what “assume A true => contradiction” means. In what context does this appear?
You have proved the confluence property in the case where we start from a valid RS and apply the BT (singles, box/line, subsets).
(i.e. final RS is independent of the order in which the BT are applied.)
But I don't think confluence property is true when you start from an invalid RS, for example when we assume a false candidate to be true and then we apply the BT and later you obtain a contradiction.
To check…