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Defdata

Register-user-combinator

Introduction

User-defined combinators add syntactic sugar on top of the core defdata language. In addition it is also possible to specify the theory support for such a construct via the :post-pred-hook-fns keyword option. (See alistof.lisp for example usage).

Example

Here is how we added alistof to the defdata language:

(register-user-combinator alistof 
 :arity 2 :verbose t
 :aliases (acl2::alistof)
 :expansion (lambda (_name _args) `(OR nil (acons ,(car _args) ,(cadr _args) ,_name)))
 :syntax-restriction-fn proper-symbol-listp
 :polymorphic-type-form (alistof :a :b)
 :post-pred-hook-fns (user-alistof-theory-events))

General Form:

(register-user-combinator combinator-name 
                          :arity num 
                          :expansion term 
                          [optional args])