Currently, LP only runs on Unix machines. You can get an implementation of LP using the world-wide web, starting at the following URL. http://www.sds.lcs.mit.edu/spd/larch/LP/news/distribution.html You can also get an implementation by anonymous ftp from the following URL. ftp://ftp.sds.lcs.mit.edu/pub/Larch/LP/ See section 2.

Although one cannot list both unknown and hmm in the same converts clause, one could add another converts clause to the trait ConvertsTrait, stating that unknown is converted, relative to the other operators, which in that case include hmm.

If you are running LP under Unix, the Unix "quit" character (usually C-g, that's control-g) will interrupt LP's execution. See section 3.6 Can I change the erase character in LP?, for other characters that aid in editing interactive input to LP. See section 3.20 How can I develop a proof that I can replay later?, for a way to avoid tedium and much direct interaction with LP.

Liquefied petroleum gas is a petroleum product separated out of natural gas and crude oil in the refining process. It looks and acts just like water, except for its boiling point. The boiling of liquefied petroleum gas produces a "steam" of a colorless, odorless flammable gas. odorant, usually ethyl mercaptan, is added to propane as a warning agent. This sulfur compound gives the gas its rotten egg odor.

The Sony MDS-W1 double MD deck will not move LP mode tracks properly. When the MDS-W1 moves LP2 and LP4 tracks to another disc it sets their SP bits on in the UTOC track header, turning LP4 tracks into (silent) SP mono and LP2 tracks into (silent) SP stereo. The track's audio data is copied properly however, so with careful use of TOC cloning to restore the LP bit in the track header, copied LP tracks will play correctly.

The Larch Prover (LP) [Garland-Guttag95] is a program that helps check and debug proofs. It is not geared toward proving conjectures automatically, but rather toward automating the tedious parts of proofs. It automates equational rewriting (proofs by normalization), but does not (by default) automatically try other proof techniques. aid the debugging of specifications (i.e.

The original reason LP was built to help debug formal specifications (see [Garland-Guttag-Horning90] and Chapter 7 of [Guttag-Horning93]). It has, however, also been used for several other purposes, including the following (reported in messages to the larch-interest mailing list, February 7 and July 23, 1994).

According to Garland (posting on the larch-interest mailing list, July 14, 1995), the erase (or rubout) character used by LP cannot be changed easily. The reason is that "LP is written in CLU, and LP's line editing features are provided by the CLU runtime environment. This environment hard-wires the delete key [DEL] as the rubout character." You can erase the current line in LP by typing a C-u (control-U). You can redisplay the current line by typing C-r.

The most important tip for using LP is to think about your conjectures, and to be very skeptical of their truth. When you first start using LP, you will be tempted to have it do the thinking for you. You may find yourself trying random proof techniques to prove the current subgoal. Resist that temptation! Curb your desire for automatic proof! Instead, use one of the following two ideas (see the section titled "Sample Proofs: how to guide a proof" in [Garland-Guttag95]).

The biggest pitfall is to not think about what you are doing, but to simply try random proof strategies. This quickly becomes frustrating. See section 3.15 Can you give me some tips on proving things with LP?, for how to work with LP in a more fruitful way. If your theory is inconsistent, proofs may not be easy, but they will always be possible. Always try to convince yourself of your theory's consistency before celebrating your proof. See section 3.

It is difficult to prove a theory is consistent using LP. However, one can profitably use LP to search for inconsistency. (See section 2.18 What pitfalls are there for LSL specifiers?, for some common LSL problems that lead to inconsistency.) One way to use LP to search for inconsistency is using the complete command. This directs LP to attempt to add enough rewrite rules to make the theory equationally complete.

LP2 mode is reportedly quite close to standard ATRAC. LP4 mode has noticeable artifacts, but is still suitable for portable applications. Brian Youn has assembled some user comments on MDLP mode's quality. There are also comments in the Sony MZ-R900 equipment browser entry.

Until there is a lab test for Lp, the current method of physical inspection of solid Appaloosas is all we have. When it has been decided that the horse is definitely non-characteristic, it should be recognized that this is still potentially a useful breeding animal. This horse many have inherited at least some of the white-helping genes that assist the white Appaloosa pattern gene (Lp).

The basic difference between LP and other theorem provers is that LP does not automatically attempt complex (i.e., interesting or speculative) proof steps. LP also has no way to write general proof strategies or tactics (as can be done in PVS, LCF, and other theorem provers). An additional convenience is that there are tools for supporting the translation of LSL specifications into LP's input format.

Yes, there is a summary of LP's commands in the section titled "Command Summary" of [Garland-Guttag95]. For ease of reference, you can find this at the following URL. http://www.sds.lcs.mit.edu/spd/larch/LP/commands/commands.html Within an LP process, you can see this by issuing the command help commands. Use help display to see help on the command display. Use display ? to see the arguments you can pass to the command display.

No, you do not need to use LSL if you use LP. LP has its own input format (although it is very similar to LSL's input format). So, many users of LP simply bypass LSL, and use LP exclusively. On the other hand, using LSL as an input format to LP has the following advantages. The LSL checker automatically generates proof management commands (scripting and logging) for LP, and helps organize theories and conjectures into files. See section 3.10 How do I use LP to check my LSL traits?.

No, if LP stops working, it may just mean that it wants more guidance from you. The way to tell if all outstanding conjectures have been proved is to use the qed command [Garland-Guttag95]. If you see the following, then you are done. All conjectures have been proved. However, if you see something like the following, then you are not done. Still attempting to prove level 2 lemma FooTheorem.2 See section 3.

See section 3.15 Can you give me some tips on proving things with LP?, and Sections 7.4-7.5 of [Guttag-Horning93], for other proof techniques.

a way of making the problem of proving things like 0 <= 2 concrete, consider the following LSL trait. This trait uses the Integer trait in Guttag and Horning's handbook (see [Guttag-Horning93], p. 163) DecimalProblem: trait includes Integer implies equations ~(1 <= 0); 0 <= 2; The problem is how to coax LP into proving these implications. The following answer is adapted from a posting of Vandevoorde's 'comp.specification.larch' (September 7, 1995).