sentences:  The doctrine was primarily established in Farris v. Glen Alden Corp., 143 A.2d 25 (Pa. 1958).Since the establishment of the doctrine in Pennsylvania, many courts have adopted their own versions of the doctrine or rejected it.The de facto merger in application allows courts to declare the nature of a transaction stated as a sale-of-assets into a merger; therefore, all rights and liabilities attached to a statutory merger would be applied.