lean2/tests/lean/run/e8.lean

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precedence `+`:65
namespace nat
variable nat : Type.{1}
variable add : nat → nat → nat
infixl + := add
end
namespace int
using nat (nat)
variable int : Type.{1}
variable add : int → int → int
infixl + := add
variable of_nat : nat → int
coercion of_nat
end
-- Using "only" the notation and declarations from the namespaces nat and int
using [notation] nat
using [notation] int
using [decls] nat
using [decls] int
variables n m : nat
variables i j : int
check n + m
check i + j
-- The following check does not work, since we are not using the coercions
-- check n + i
-- 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
check i + n
check n + i