8 Feb
2008
8 Feb
'08
9:59 p.m.
On Fri, Feb 08, 2008 at 06:47:51PM -0800, Ryan Ingram wrote:
I'm assuming you mean the rule described in http://en.wikibooks.org/wiki/Formal_Logic/Sentential_Logic/Inference_Rules
type Disj a b = Either a b
disj_elim :: Disj a b -> (a -> c) -> (b -> c) -> c disj_elim (Left a) a2c b2c = a2c a disj_elim (Right b) a2c b2c = b2c b
If you know "either a is true, or b is true" and you know "from a, I can prove c", and you know "from b, I can prove c", then you can prove c.
aka: import Data.Either type Disj = Either disj_elim = either Stefan