-- Define a "fake" type to simulate the natural numbers. This is just a test. Variable N : Type Variable lt : N -> N -> Bool Variable zero : N Variable one : N Variable two : N Variable three : N Infix 50 < : lt Axiom two_lt_three : two < three Definition vector (A : Type) (n : N) : Type := Pi (i : N) (H : i < n), A Definition const {A : Type} (n : N) (d : A) : vector A n := fun (i : N) (H : i < n), d Definition update {A : Type} {n : N} (v : vector A n) (i : N) (d : A) : vector A n := fun (j : N) (H : j < n), if (j = i) d (v j H) Definition select {A : Type} {n : N} (v : vector A n) (i : N) (H : i < n) : A := v i H Definition map {A B C : Type} {n : N} (f : A -> B -> C) (v1 : vector A n) (v2 : vector B n) : vector C n := fun (i : N) (H : i < n), f (v1 i H) (v2 i H) print Environment 10 Check select (update (const three false) two true) two two_lt_three Eval select (update (const three false) two true) two two_lt_three Check update (const three false) two true print "\n--------" Check @select print "\nmap type ---> " Check @map print "\nmap normal form --> " Eval @map print "\nupdate normal form --> " Eval @update