90bfd84a07
In the standard library, we should use explicit universe variables for universe polymorphic definitions. Users that want to declare universe polymorphic definitions but do not want to provide universe level parameters should use Type _ or Type*
39 lines
858 B
Text
39 lines
858 B
Text
set_option pp.coercions false
|
|
|
|
check if tt then "a" else "b"
|
|
|
|
/- Remark: in the standard library nat_to_int and int_to_real are has_lift instances
|
|
instead of has_coe. -/
|
|
constant int : Type
|
|
constant real : Type
|
|
constant nat_to_int : has_coe nat int
|
|
constant int_to_real : has_coe int real
|
|
attribute [instance] nat_to_int int_to_real
|
|
|
|
constant sine : real → real
|
|
constants n m : nat
|
|
constants i j : int
|
|
constants x y : real
|
|
|
|
check sine x
|
|
check sine n
|
|
check sine i
|
|
|
|
constant int_has_add : has_add int
|
|
constant real_has_add : has_add real
|
|
attribute [instance] int_has_add real_has_add
|
|
|
|
check x + i
|
|
|
|
/- The following one does not work because the implicit argument ?A of add is bound to int
|
|
when x is processed. -/
|
|
check i + x -- FAIL
|
|
|
|
/- The workaround is to use the explicit lift -/
|
|
check ↑i + x
|
|
|
|
check x + n
|
|
|
|
check n + x -- FAIL
|
|
|
|
check ↑n + x
|