precedence `+`:65 namespace nat constant nat : Type.{1} constant add : nat → nat → nat infixl + := add end nat namespace int open nat (nat) constant int : Type.{1} constant add : int → int → int infixl + := add constant of_nat : nat → int coercion of_nat end int constants n m : nat.nat constants i j : int.int section open [notation] nat open [notation] int open [decls] nat open [decls] int check n+m check i+j -- check i+n -- Error end namespace int open [decls] nat (nat) -- Here is a possible trick for this kind of configuration definition add_ni (a : nat) (b : int) := (of_nat a) + b definition add_in (a : int) (b : nat) := a + (of_nat b) infixl + := add_ni infixl + := add_in end int section open [notation] nat open [notation] int open [declarations] nat open [declarations] int check n+m check i+n check n+i end section open nat open int check n+m check i+n end