15 lines
429 B
Text
15 lines
429 B
Text
inductive formula :=
|
|
| eqf : nat → nat → formula
|
|
| impf : formula → formula → formula
|
|
|
|
namespace formula
|
|
definition denote : formula → Prop
|
|
| denote (eqf n1 n2) := n1 = n2
|
|
| denote (impf f1 f2) := denote f1 → denote f2
|
|
|
|
theorem denote_eqf (n1 n2 : nat) : denote (eqf n1 n2) = (n1 = n2) :=
|
|
rfl
|
|
|
|
theorem denote_impf (f1 f2 : formula) : denote (impf f1 f2) = (denote f1 → denote f2) :=
|
|
rfl
|
|
end formula
|