What is the missing step in this proof?
BAC ACB

BDE DEB

ADE DEC

BAC BDE

ABC DBE

Proof:
Statement Reason
1. given
2. Addition Property of Equality
3. using common denominators
4. AB = AD + DB
CB = CE + EB segment addition
5. Substitution Property of Equality
6. ABC DBE Reflexive Property of Congruence
7. ABC ~ DBE SAS similarity criterion
8. Corresponding angles of similar triangles are congruent.
9. || If the corresponding angles formed by two lines cut by a transversal are congruent, then the lines are parallel.

Question

What is the missing step in this proof?
BAC    ACB

BDE    DEB

ADE    DEC

BAC    BDE

ABC    DBE

Proof: 
Statement	Reason
1.  	given
2.  	Addition Property of Equality
3.  	using common denominators
4. AB = AD + DB
   CB = CE + EB	segment addition
5.  	Substitution Property of Equality
6. ABC    DBE	Reflexive Property of Congruence
7.   ABC ~   DBE	SAS similarity criterion
8. 	Corresponding angles of similar triangles are congruent.
9.   ||  	If the corresponding angles formed by two lines cut by a transversal are congruent, then the lines are parallel.