22 lines
929 B
Lua
22 lines
929 B
Lua
|
local env = empty_environment()
|
||
|
|
env = add_decl(env, mk_var_decl("A", Bool))
|
||
|
|
local A = Const("A")
|
||
|
|
local x = Const("x")
|
||
|
|
env = add_decl(env, mk_axiom("magic", Pi(x, Bool, x)))
|
||
|
|
local saved_env = env
|
||
|
|
env = add_decl(env, mk_axiom("Ax", A))
|
||
|
|
env = add_decl(env, mk_definition("T1", A, Const("Ax")))
|
||
|
|
-- The check mk_theorem("Ax", A, Const("T1")) failes because env
|
||
|
|
-- contains the axiom named Ax.
|
||
|
|
-- So, we cannot transform Ax into a theorem that depends on itself.
|
||
|
|
-- (This is good)
|
||
|
|
assert(not pcall(function() env:replace(check(env, mk_theorem("Ax", A, Const("T1")))) end))
|
||
|
|
assert(env:find("Ax"):is_axiom())
|
||
|
|
local magic = Const("magic")
|
||
|
|
-- Replace axiom Ax with the theorem Ax that is checked in the old
|
||
|
|
-- environment saved_env. Everything works because env is a descendant
|
||
|
|
-- of saved_env
|
||
|
|
env = env:replace(check(saved_env, mk_theorem("Ax", A, magic(A))))
|
||
|
|
assert(not env:find("Ax"):is_axiom())
|
||
|
|
assert(env:find("Ax"):is_theorem())
|