ichael and Derrick each completed a separate proof to demonstrate that corresponding angles AKG and ELK are congruent. Identify the proof that was completed incorrectly, and explain the error.

Michael's Proof:

1.line AB∥line EF with transversal segment GJ (Given)
2.∠AKG is congruent to ∠AKL (Vertical Angles Theorem)
3.∠BKL is congruent to ∠ELK (Alternate Interior Angles Theorem)
4.∠AKG is congruent to ∠ELK (Transitive Property)

Derrick's Proof:

a.line AB∥line EF with transversal segment GJ (Given)
b.∠AKG is congruent to ∠BKL (Vertical Angles Theorem)
c.∠BKL is congruent to ∠ELK (Alternate Interior Angles Theorem)
d.∠AKG is congruent to ∠ELK (Transitive Property)

Identify the proof with the error and explain the mistake.