At:
list exists exists122111112
1.
T: Type
2.
eq: {T=}
3.
eq TT
4.
P: TType
5.
L: T List
6.
u: T
7.
v: T List
8.
xv.P(x) (x:{x:T| x(eq) v }. P(x))
9.
xv.P(x) (x:{x:T| x(eq) v }. P(x))
10.
x: T
11.
if eq(x,u) true else x(eq) v fi
12.
P(x)
13.
eq(x,u) = false
14.
False x = u
15.
False (x = u)
x = u
}
T
T
x
(
true
