NameAbraham Yost 
Birth10 May 1784, York Co, PA1719
Parent-Proof notes for Abraham Yost
His birth and baptism was recorded at Fissel’s Church. His parents were Nicolaus Yost and wife Regina.
My Comments notes for Abraham Yost
The record of his birth is critical since the baptism record says his mother was Regina and it occurred after the 1779 deed wherein the wife of Nichoas Yost was said to be Rachel and before the 10 May 1785 date when Nicholas Yost wrote his will and stated his wife’s name was Rachel.
So it is a problem that Nicholas and Rachel/Regina may also have had another son born a month or two earlier than Abraham. I find it interesting that the date of the will was exactly a year later than Abraham’s recorded birth and wonder whether the explanation might be that the church record is in error and that Abraham was born 10 May 1785 and his birth was the motivating cause of Nicholas writing or updating his will. This solves the Jacob problem and does not negate the conclusion that Rachel and Regina were the same person.