Termination Analysis by Learning Terminating Programs

We present a novel approach to termination analysis. In a first step, the analysis uses a program as a black-box which exhibits only a finite set of sample traces. Each sample trace is infinite but can be represented by a finite lasso. The analysis can "learn" a program from a termination proof for the lasso, a program that is terminating by construction. In a second step, the analysis checks that the set of sample traces is representative in a sense that we can make formal. An experimental evaluation indicates that the approach is a potentially useful addition to the portfolio of existing approaches to termination analysis

Real Property - Restrictive Covenants - Termination by Declaratory Judgment

Appellant originally owned all of a certain tract of land upon which his home was built. In 1942 he conveyed one lot to the predecessor in title of the appellees, including in the deed a covenant restricting the lot to residential uses. Subsequently he conveyed three other lots carved from the original tract without inserting restrictive covenants in the deeds. The appellees brought suit for a declaratory judgment invalidating the restrictive covenant on their lot, and such judgment was granted. While an appeal from this decree was pending, appellant sold his home to a rural electric co-operative for admittedly commercial uses, but he retained a portion of the original tract. Held, affirmed. The right to enforce the covenant is lost by abandonment, waiver, and by a change in the character of the neighborhood which renders its enforcement no longer practicable. Bagby v. Stewart\u27s Executors, (Ky. 1954) 265 S.W. (2d) 75

Legislation - Application of Merchantile License Tax to Lawyers

The Philadelphia City Council passed an ordinance entitled An Ordinance--To provide for revenue by imposing a mercantile license tax on persons engaging in certain businesses including manufacturing, professions, occupations, trades, vocations, and commercial activities in the City of Philadelphia. . . . Under this ordinance the city required lawyers to register, pay a registration fee, and pay a tax on a percentage of their gross volume of business; thereupon, mercantile licenses were issued to them. The city charter required each ordinance to deal with one subject only and to express that subject in the title. The application of the ordinance to lawyers was attacked under the sponsorship of the Philadelphia Bar Association, and the lower court enjoined enforcement against lawyers. On appeal, held, reversed. Sterling v. Philadelphia, 378 Pa. 538, 106 A (2d) 793 (1954)

Negligence - Res Ipsa Loquitur - Application to Multiple Defendants in the Alternative

Appellant, a minor, was injured by the explosion of an aerial bomb which he found on a county fair ground. Two of the defendants admitted having brought aerial bombs to the fair but each entered evidence which if believed would show that he had not left the article which injured the appellant. These two defendants were completely independent of each other and it was admitted that both could not be responsible for the injury to the child. The lower court instructed the jury that if they could not determine which of the two defendants was actionably negligent, they were compelled to exonerate both. Held, reversed. An instruction based on res ipsa loquitur should have been given and if the jury was unable to determine which of two defendants was guilty of actionable negligence, both should have been held liable. Litzmann v. Humboldt County, (Cal. App. 1954) 273 P. (2d) 82

Real Property - Elimination of the Straw Man in the Creation of Joint Estates in Michigan

That joint ownership is a popular form of holding title to real property is undeniable. A husband and wife are especially likely to consider this form of ownership as natural and desirable because it emphasizes the concept of marriage as a partnership and gives both partners control over and ownership in the family property. In addition to these factors, joint ownership is popular because of the right of survivorship which is incident to it. In this feature the layman sees, or thinks he sees, the opportunity to avoid a probate proceeding, the estate tax, and the lawyer\u27s fee. It is not the purpose here to discuss the advantages and disadvantages of joint ownership but it is hardly rash to observe that the property owner cannot, by the simple strategem of taking title in his own name and that of his proposed beneficiary, evade either the tax collector or the lawyer and his fee. The entire value of property held in joint tenancy or by the entireties must be included in the estate of the decedent for federal estate tax purposes, and unless the entire estate, both real and personal property, is jointly held, or is very small, or is uncontested, probate is inevitable. Even if these hurdles are cleared, the death of the co-owner must still be proved and entered upon the records to clear the title, thus bringing the lawyer into the scene again. But given all these factors, joint ownership of property can still be a very valuable device and one which every lawyer will want to utilize at some time. It is in the interest of lawyer and layman alike that the process culminating in joint ownership be as simple as possible

Instantiation-Based Interpolation for Quantified Formulae

Interpolation has proven highly effective in program analysis and verification, e. g., to derive invariants or new abstractions. While interpolation for quantifier free formulae is understood quite well, it turns out to be challenging in the presence of quantifiers. We present in this talk modifications to instantiation based SMT-solvers and to McMillan\u27s interpolation algorithm in order to compute quantified interpolants

Future Interests - Restraints on Alienation - Option to Repurchase at a Fixed Price

Shortly after his second marriage in 1925, plaintiff deeded a house and two lots to the parents of his first wife. The grantees, along with the plaintiff, had occupied the premises since the first wife\u27s death. The deed contained a provision that if the second parties do not wish at any time to use the property as a home, the first parties shall have the first privilege to purchase the above described property at any future time at the price stated in this deed, viz., $4,000. In 1952, after the death of both grantees and when the property was worth$12,000, plaintiff tendered the purchase price to the heirs of the grantees and demanded a deed. Upon their refusal to convey, he brought suit for specific performance, which was granted by the lower court. On appeal, held, affirmed, two justices dissenting. Lantis v. Cook, 342 Mich. 347, 69 N.W. (2d) 849 (1955)