Equality between functionals in the presence of coproducts

D.J. Dougherty, R. Subrahmanyam
Proceedings of Tenth Annual IEEE Symposium on Logic in Computer Science  
We consider the lambda calculus obtained from the simply typed calculus by adding products, coproducts, and a terminal type. We prove the following theorem: The equations provable in this calculus are precisely those true in any set-theoretic model with an infinite base type. ]
doi:10.1109/lics.1995.523263 dblp:conf/lics/DoughertyS95 fatcat:uuzcp3dxnvdvnc64fm6n7yt5yu