And now back to our regularly scheduled programming…

If whatever (B) happens actually only happens at times (t(n-1) + t(n-2) + … t (n-k)), then nothing happens at time t (i.e. ~∃x(Bx(t)). If no-thing happens at time t (i.e. ~∀x(Bx(t))), then nothing ever happens. If it is granted that "what happens at t" is B itself, then perdurantism is false. Otherwise, if there is no B, then there is no sense in speaking of parts of B.

The canonical example for (but really just "in") perdurantism qua entailment of the theory of special relativity (TSR), is a train collision, or mutatis mutandis a train passing a station. The point is supposed to be that there is no unique time in which "the train T passes the station S", rather that there are only time slices which correspond to relative observations. If so, then those observation-slices are themselves divisible into "smaller" slices, and don't exist in their own right. If it is granted that observation is instantaneous, then we're getting all Thomistic.

What is a "unique" time? There is no "singly valid" (unique) observational standpoint on perdurantism, so, by extension, there is no singly valid (unique) event. That is fallacious, however. Chalk it up to my abiding worries about woebegone simultaneity and truth-makers as a metaphysical family secret. Plus my profound dissatisfaction with perdurantist (ethical, logical, etc.) entailments.

∃ is {& exist;}
∀ is {& forall;}
↔ is {& harr;}
≡ is {& equiv;}
∴ is {& there4;}
□ is {& #9633;}
◊ is shift+alt/option v (auf 'ner deutschen Tastatur) or ◊ {& loz;}
∩ {& #x2229;} (Where members of set X are members of A both and B.)
U is… U (Where members of set X are members of either A or B.)

Logical updates…

Good to know, for HTML, at least: 

∃ is {& exist;}
∀ is {& forall;}
↔ is {& harr;}
≡ is {& equiv;}
∴ is {& there4;}
□ is {& #9633;}
◊ is shift+alt/option v (auf 'ner deutschen Tastatur) or ◊ {& loz;}
∩ {& #x2229;} (Where members of set X are members of A both and B.)
U is… U (Where members of set X are members of either A or B.)

[Remove space between & and the sequalia.]

Here are my poor man's HTML-free stabs at it…

$x : there is an x
A*x : for all x
<--> : iff
=* : means, is semantically entailed by
‹› : it is contingent that
[] : it is necessary that
Ω* : intersection of
∆· : therefore

All of these only work (or work best) on a German keyboard (as I have set on my Mac).

So, let's try this again…

For : "Every dog (Dx) is loved by (Lyx) at least one man (My). herefore, at least one man loves every dog (~∀y∃x(~∃x~Lyx)) loves every dog (Dx)." 

Valid or invalid? Show your work!

~(Dx --> ($y(My ^ Lyx)) ^ --> (A*x$x(Dx ^ My ^ Lyx))) 

De modo studendi…

Thomas Aquinas to Brother John:

EPISTOLA DE MODO STUDENDI

A LETTER ON THE METHOD OF STUDY

Quia quaesisti a me, in Christo mihi carissime Ioannes, qualiter te studere oporteat in thesauro scientiae acquirendo, tale a me tibi traditur consilium: ut per rivulos, non statim in mare, eligas introire, quia per faciliora ad difficiliora oportet devenire. Haec est ergo monitio mea et instructio tua. Tardiloquum te esse iubeo et tarde ad locutorium accedentem; conscientiae puritatem amplectere. Orationi vacare non desinas; cellam frequenter diligas si vis in cellam vinariam introduci. Omnibus te amabilem exhibe; nihil quaere penitus de factis aliorum; nemini te multum familiarem ostendas, quia nimia familiaritas parit contemptum et subtractionis a studio materiam subministrat; de verbis et factis saecularium nullatenus te intromittas; discursus super omnia fugias; sanctorum et bonorum imitari vestigia non omittas; non respicias a quo audias, sed quidquid boni dicatur, memoriae recommenda; ea quae legis et audis, fac ut intelligas; de dubiis te certifica; et quidquid poteris in armariolo mentis reponere satage, sicut cupiens vas implere; altiora te ne quaesieris. Illa sequens vestigia, frondes et fructus in vinea Domini Sabaoth utiles, quandiu vitam habueris, proferes et produces. Haec si sectatus fueris, ad id attingere poteris, quod affectas.

Because you have asked me, John, my dearest friend in Christ, how you should study to amass the treasure of knowledge, such is the advice I give to you. You should choose to enter not immediately into the ocean depths, but rather through small streams, for one should reach more difficult matters by going through the easier ones first. This is, therefore, my admonition and your instruction. I bid you be slow to speak and slow to approach the chat-room1. Embrace purity of conscience. Do not fail to have time for prayer. You should frequently choose your own room if you wish to be led into the wine cellar. Present yourself as amiable to all. Do not look for deep, hidden meanings in the deeds of others. To no one should you show yourself to be too familiar, because too much familiarity gives birth to contempt and provides from its eagerness the raw material for backsliding. You should in no way involve yourself concerning the words and deeds of worldly people. Above all else you should flee from common conversation. You should not fail to imitate the steps of the saints and all good people. You should not consider the source from which you hear something, but whatever good is spoken, commit it to memory. Those things that you read and hear, make sure that you understand them. Make yourself certain about doubtful matters, and make it your business to shelve in the bookcase of your mind whatever you can, as if desiring to fill a vase. Do not seek the matters that are above you. Following those well-known paths you will bring forth and produce, as long as you have life, branches and fruits useful in the vineyard of the Lord of Hosts. If you eagerly follow these points, you will be able to attain that which you are striving after.

–––––––––––
1 I have for the most part kept this a fairly literal translation, attempting where reasonable to keep if not precise word order, at least the order of clause arrangement as close as possible to the original. My choice of “chat-room” for locutorium, however may seem a bit too colloquial, but there was a reason for this decision. Aquinas’ metaphors are quite vivid and, for the most part, come across well into modern expression without significant change. The word locutorium refers to a parlor, or place to gather for conversation, so “chat-room” is not altogether inappropriate. Of course, it also suggests the modern connotation of the Internet chat-room, and while Aquinas certainly could not have intended this, I think the modern reader who has this in mind will receive in a more personal way the admonition that Aquinas intended. -- Steve Perkins, 2004

L∅γι⊂αl ∫ϒmβ∅l∫...

Finally found the kind of guide I was looking for!

http://www.danshort.com/HTMLentities/index.php?w=maths

{p : p it is raining}
{q : q the ground is wet}
p ⊃ q, p ∴ q

p ∴ p

"The ground is wet." =
{Wx : x is wet}
{Gx : x is the ground}
(∃x)(Wx ∧ Gx)

"The ground is not wet." =
{Wx : x is wet}
{Gx : x is the ground}
(∃x)(~Wx ∧ Gx)

HTML for columns in Blogger...

{table border="1"}{colgroup}{col valign="top" width="50%"}{colgroup}{col valign="top" width="50%"}{thead}{tr}{th}LATIN{/th}{th}ENGLISH{/th}{/tr}{/thead}{tbody}{tr}{td}Put the Latin here{/td}{td}Put Enlgish here{/td}{/tr}{/tbody}{/table}

(Replace {} with <>.)

I got this code in the combox of this post at the Smithy. Sullivan posted a lovely little poem by Notker of St Gall and I will now put it in a column-box to get a feel for this HTML.

LATIN

ENGLISH

Hoc praesens diecula loquitur praelucida, adaucta longitudine, quod sol verus radio sui luminis vetustas mundi depulerit genitus tenebras. Nec nox vacat novi sideris luce, quod magorum oculos terruit scios: Nec gregum magistris defuit lumen, quos praestrinxit claritas militum dei. Gaude, dei genetrix, quam circumstant obstetricum vice concinentes angeli gloriam deo.

This present little day proclaims, illumined, its length increased, that the true Sun by the ray of its light has driven off the ancient darknesses of the world. Nor does this night lack the light of the new star, which terrified the knowing eyes of the magi: Nor was light lacking for the masters of their flocks, who were stricken by the brightness of the soldiers of God. Rejoice, O god-bearer, who instead of midwives are surrounded by angels singing in harmony glory to God.