At:
list exists is member lemma1121111
1.
T: Type
2.
eq: TT
3.
(x,y:T. eq(x,y) x = y) & eq TT
4.
P: TProp
5.
L: T List
6.
x: T
7.
P(x)
8.
u: T
9.
v: T List
10.
x(eq) v yv.P(y)
11.
x(eq) (u.v)
12.
eq(x,u)
P(u)
By:
Analyze 3
THEN
Witness3 x
THEN
With u (Analyze -1)
Generated subgoal: