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Hello, Not really that common in literature, but in Hindley and Selding’s book, Lambda Calculus and Combinators, they use respectively ν and μ to name those congruence rules, both in the untyped and the typed case. They claim to have taken that from Curry & Feys. Best regards -- Filippo Sestini [email protected] (+39) 333 6757668 > On Jul 3, 2017, at 8:04 PM, Philip Wadler <[email protected]> wrote: > > [ The Types Forum, http://lists.seas.upenn.edu/mailman/listinfo/types-list ] > > Reduction for the simply-typed call-by-value lambda calculus consists of > the β rule, > > (λx.N)V ⟹ N[x:=V] > > and the congruence rules > > L ⟹ L′ > ------------ > L M ⟹ L′ M > > M ⟹ M′ > ------------ > V M ⟹ V M′ > > Question: Is there a standard greek letter for naming the congruence rules, > such as κ or γ? Or any other relevant naming convention? > > Cheers, -- P > > > . \ Philip Wadler, Professor of Theoretical Computer Science > . /\ School of Informatics, University of Edinburgh > . / \ http://homepages.inf.ed.ac.uk/wadler/ > The University of Edinburgh is a charitable body, registered in > Scotland, with registration number SC005336.
