existence

mcguireh

Proof of the following formula: 

∃x[x² = x]

(#)     Theorem and subgoals
      We start working with the formula being proved
as follows:
(1)     
∃x[x² = x]
      Assigning "x := 1" in that formula yields:
(2)     
1² = 1
          ≡      by simplifying
(3)     
true
      That concludes the proof.

identification:
1233773436656
1233773429281
7375