At:
is intersection implies exists element12221
1.
T: Type
2.
eq: {T=}
3.
L: T List
4.
M: T List
5.
u: T
6.
v: T List
7.
v(eq)M (x:{x:T| x(eq) v }. x(eq) M)
8.
v(eq)M
9.
v(eq)M
x:{x:T| if eq(x,u) true else x(eq) v fi }. x(eq) M
By:
Analyze -1
THEN
Trivial
Generated subgoals:
}
(eq)M 
(
x:{x:T| x(
eq) v }. x(
v
true