Author Topic: Term Post Eye Tiable i.e. PET  (Read 1061 times)

jarnos

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Re: Term Post Eye Tiable i.e. PET
« Reply #15 on: January 26, 2021, 06:38:55 PM »
In the image I apply terms of graph theory to knots, which helps in talking about more complicated knots.  In graph theory an edge that connects vertex to itself is called loop, self-loop or a buckle. That is what is usually called eye when talking about knots. More general eye corresponds to cycle. Post eye tiable corresponds to wend (i.e. working end) not needed before connecting (i.e. tying) the enclosing edge of the cycle. (There is also a geometrically smaller cycle in the knot.) Core or nub corresponds to vertex.
Jarno Suni

agent_smith

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Re: Term Post Eye Tiable i.e. PET
« Reply #16 on: January 27, 2021, 02:52:59 AM »
Hello jarnos,
Hope 2021 is shaping up well for you.

Everything I write herein is intended in good faith (just to remove any doubt)...

I have carefully read through all of your posts - including your latest post.

Okay... I am left wondering about exactly what you are trying to achieve or what exactly is your proposition?

There doesn't appear to be a question in your most recent post.
Your post appears to be framed as a statement of fact, rather than a question seeking an answer.

May I please direct some questions to you as follows:?
1. Do you have a concern with the concept of 'PET'?
2. Is the term 'PET' and its basic meaning a source of irritation to you?
3. Do you believe that the term 'PET' is ill defined - and needs to be revised?
4. Do you fundamentally disagree with some knot terminology that has been used (eg eye instead of loop)?
5. Do you believe that you most recent posted image is proof that the concept of 'PET' is flawed or wrong in some way?
6. Do you believe that the concept of 'PET' is limited only to certain classes of knots - and cannot be universally applied to all categories of eye (loop) knots?

If you could provide some answers to these questions - perhaps others might be able to supply constructive discussion...

Thanks in advance :)

jarnos

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Re: Term Post Eye Tiable i.e. PET
« Reply #17 on: January 28, 2021, 05:27:23 PM »
Also Robert G Birch defines eye (knot) in his "Annotated Glossary for Practical Knot Tyers" that can be found by title "Knotting terminology" in the linked page in reply #1.

Eye is not just a bight. It needs also a nub by which both legs of the bight are connected. When you have an eye, you already have connected the legs of the bight in a nub and you might not have to tie anything thereafter. That is why talking about post eye tiable is conceptually troubled.

If we want to define an eye knot that has more than one nub (like in my previous post), it might be good to expand its definition or add another term for such a structure.

It is sad that the concept of loop in graph theory is not analogous to the concept of loop when talking about knots; it corresponds to eye, instead. Traditional naming of eye knots as loop knots may also cause some confusion.
Jarno Suni

agent_smith

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Re: Term Post Eye Tiable i.e. PET
« Reply #18 on: January 29, 2021, 01:54:31 AM »
Hello and greetings jarnos,

I am continuing to engage with you in good faith.
I am trying to zero-in on the source of your concerns with respect to the concept of 'PET' (Post Eye Tiable).

I don't speak your first language - I only speak and understand English (sorry). So I can only correspond in English!

Okay, I will try to extract some meaning from your most recent post:

Quote
Also Robert G Birch defines eye (knot) in his "Annotated Glossary for Practical Knot Tyers"
Please be aware that Robert Birch did not invent the concept of 'PET' - he merely attempts to report it.
I have read his document and here is the definition he typed:

Per Robert Birch:
An eye knot is PET (post eye tiable) if it can be made with the eye around a post, without
accessing either end of the post and without needing to form a preliminary knot before passing
the line around the post
.

The first part of his definition is incoherent and confused - and needs to be re-worded.
The second part (in red font) is accurate.

I think it might be useful to specify an object such as a fixed ring within the definition of 'PET' (Note: A fixed ring is different to a post).
By specifying a ring, it narrows the definition.

Quote
Eye is not just a bight.
An 'eye' is not a 'bight' (they are two different descriptors).
However, I can see that in the case of a #1047 F8 - when it is tied-in-the-bight, the 'eye' can be formed and sized before the core is tied.
I can see your correlation between a 'bight' and an 'eye'.
In this example, the 'bight' of rope in the F8 is destined to become the 'eye'! The 'bight' is (in effect) a preliminary 'eye'.

Quote
It needs also a nub by which both legs of the bight are connected.
The term 'PET' only refers to a situation where the beginnings of an eye can be formed and sized without any conditional knot pre-existing in the line.
I used the word 'beginnings' - to emphasize that once the 'eye' has been formed into the desired size, the core of the knot can then be completed.
Lets take a fixed ring as an example.
In a 'PET' knot, the line can be passed through a fixed ring and then the core of the knot is tied and completed. No pre-existing knot is conditional.
In the case of #1047 F8, there is no way that the 'eye' can be formed through a fixed ring without a pre-existing knot. That is, it is conditional that a knot is tied in the line before feeding the rope through the fixed ring.

The line that is passed through the fixed ring will become the 'eye'.
As the line is fed through the fixed ring, it is not yet tied into the core (nub).
It is in a preliminary state - because at this point in time, it is not yet fixed.

#1047 F8 is an interesting case because it can also be tied in-the-bight. That is, it is 'TIB'.
The initial bight that is formed will become the 'eye'.

SUMMARY:
If it is necessary to specify a fixed ring within the definition of PET - I am in favor of such a modification.
By narrowing the definition of PET to eye knots that can be tied to a fixed ring without any pre-existing knot - it will help to remove doubt.
The #1047 F8 is 'TIB', and so technically, the 'preliminary eye' can be formed and sized before any knot is tied in the line. But if we narrow the definition to include a fixed ring, this eliminates #1047 F8.

Let me know what you think and if you agree - perhaps we can gather support?
« Last Edit: January 29, 2021, 02:03:47 AM by agent_smith »

DerekSmith

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Re: Term Post Eye Tiable i.e. PET
« Reply #19 on: February 02, 2021, 08:24:15 PM »
Per Robert Birch:
An eye knot is PET (post eye tiable) if it can be made with the eye around a post, without
accessing either end of the post and without needing to form a preliminary knot before passing
the line around the post
.

The first part of his definition is incoherent and confused - and needs to be re-worded.
The second part (in red font) is accurate.

Personally I find the Birch definition to be totally correct and to aptly describe the restrictions imposed on a knot for it needing to be defined as PET.  However, for completeness he might have written "around a post or ring" in order to ensure clarity that the formed loop could not simply be passed over the  fixing point.

However, despite this, the term PET is virtually meaningless as any desired components or 'pre-knots'  required can simply be tied with the WE after it has been passed around the fixing point, then drawn back around the fixed object / ring  leaving a protoloop around the object, then finish off the knot using the WE.

Unless we are dealing with a ring whose eye is so tiny that only a single cord diameter can be passed through it, then the whole concept of PET is meaningless.

Derek

SS369

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Re: Term Post Eye Tiable i.e. PET
« Reply #20 on: February 02, 2021, 08:39:04 PM »
Of course a PET eye knot can be tied without going through or around anything.

I think most of the forum members likely understand the PET acronym to date and we are just going on and on as we do about names of knots or their parts.

Perhaps people don?t like the P (post)?
After eye tiable AET more likable. ? LOL
And on it goes...

SS

Dan_Lehman

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Re: Term Post Eye Tiable i.e. PET
« Reply #21 on: February 03, 2021, 12:51:45 AM »
Per Robert Birch:
An eye knot is PET (post eye tiable) if it can be made with the eye around a post, without
accessing either end of the post and without needing to form a preliminary knot before passing
the line around the post
.

The first part of his definition is incoherent and confused - and needs to be re-worded.
The second part (in red font) is accurate.

Personally I find the Birch definition to be totally correct and to aptly describe the restrictions imposed on a knot for it needing to be defined as PET.  However, for completeness he might have written "around a post or ring" in order to ensure clarity that the formed loop could not simply be passed over the  fixing point.

However, despite this, the term PET is virtually meaningless as any desired components or 'pre-knots'  required can simply be tied with the WE after it has been passed around the fixing point, then drawn back around the fixed object / ring  leaving a protoloop around the object, then finish off the knot using the WE.

Unless we are dealing with a ring whose eye is so tiny that only a single cord diameter can be passed through it, then the whole concept of PET is meaningless.

Derek
Egadz!   :o

Let's NOT confuse things with reference to a "post" qua tied-to
object --ThAT is readily and best avoided!
One might describe a climber's attaching life-safety rope
to one's own harness, being able to reeve the line through
the harness devoid of any existing/pre-tied knot in the line
AND THEN tying the eye knot in One Fell Soup (Roy Blount, thank you).

One doesn't need graph theory here.

AND the adjectival compound term is rightly put 'post-eye'
--nb: hyphenated to bind the terms into proper primary and
modifying roles in forming the adjective to "tiable".  (Which
maybe Knot Tyers might care to re-spell?   ;)


Now, I'll await enlightenment on what looks like nonsense
--to wit:
Quote
the term PET is virtually meaningless as
 any desired components or 'pre-knots'  required
 can simply be tied with the WE after it has been passed around the fixing point,
 [sounds like "post-eye" here!?]
 then drawn back around the fixed object / ring
  leaving a protoloop
  [are there sanitizers for this?  ;D  ]
 around the object,  then finish off the knot using the WE.
This makes no better sense with my facemask over my eyes.

--dl*
====

agent_smith

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Re: Term Post Eye Tiable i.e. PET
« Reply #22 on: February 10, 2021, 06:30:14 AM »
Quote
However, despite this, the term PET is virtually meaningless as any desired components or 'pre-knots'  required can simply be tied with the WE after it has been passed around the fixing point, then drawn back around the fixed object / ring  leaving a protoloop around the object, then finish off the knot using the WE.
I am going to pick this apart in detail for analysis...

In detail:
[the term PET is virtually meaningless]
The term 'PET' can have meaning - however, it has to be properly defined.
Elon Must always declares: To get the right answers, you must ask the right questions.

Quote
as any desired components or 'pre-knots'  required can simply be tied with the WE after it has been passed around the fixing point,
In my view, the key point is whether or not it is conditional that a knot is pre-existing in the line.
That is; if it is a necessary condition that a knot must be pre-existing in the line before the working end is fed through an object (a fixed ring) - it isn't deserving of the title 'PET'.

Quote
then drawn back around the fixed object / ring  leaving a protoloop around the object, then finish off the knot using the WE.
I think this can be resolved with carefully drafted language.

...

I am not in favor of the Robert Birch definition where a reference to a 'post' is made.
The term 'post' may be problematic. Many people might visualize a post as a linear object embedded in the ground (eg a fence post).
In such a case, only one end of the 'post' is visible (the opposite end is buried in the ground and is invisible).
Also, there will always be people who will argue that you could simply slip the eye of the knot over the end of the 'post' - so its an artificial construct.

However, if the language is drafted to specify a 'fixed ring' (eg an eye bolt) - this removes arguments over the ends of the object/post you are tying to (because there are no 'ends' in a ring).
If the working end can be fed through a fixed ring - so as to enable the eye to be formed and sized without any pre-existing knot in the line, the knot is deserving of the title 'PET'.

Some may dislike the qualification of a fixed ring.
An alternative definition might be drafted around the phrase; 'fed through an object'.

The diameter of the opening (eg the diameter of a ring) does not disturb the definition.
However, the diameter of the opening must be sufficient to enable the line to pass through.

In terms of #1047 Figure 8 eye/loop knot, it is possible to argue that it is 'PET' - because the 'TIB' tying method initially forms a 'bight' - and after the bight is formed, the remainder of the knot is tied. One could postulate that the forming of the initial 'bight' constitutes the beginnings of an 'eye' - with no pre-existing knot in the line. And therefore one could argue that #1047 F8 is 'PET'.
If the line has to be fed through a fixed ring, this removes #1047 F8 as a candidate for title of 'PET'.

The English language is complex...

jarnos

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Re: Term Post Eye Tiable i.e. PET
« Reply #23 on: February 11, 2021, 11:11:29 PM »

Personally I find the Birch definition to be totally correct and to aptly describe the restrictions imposed on a knot for it needing to be defined as PET.  However, for completeness he might have written "around a post or ring" in order to ensure clarity that the formed loop could not simply be passed over the  fixing point.

However, despite this, the term PET is virtually meaningless as any desired components or 'pre-knots'  required can simply be tied with the WE after it has been passed around the fixing point, then drawn back around the fixed object / ring  leaving a protoloop around the object, then finish off the knot using the WE.

Unless we are dealing with a ring whose eye is so tiny that only a single cord diameter can be passed through it, then the whole concept of PET is meaningless.

Derek

The advantage of so called PET knot, call it X eye knot, is that there is no need to do so much threading or drawing the cord forth and back to tie the knot.

The definition of X eye knot does not require mentioning a ring or a post or any such object: Suppose you follow the cord starting from the standing part into the knot and when you enter the outgoing leg of the eye, the eye knot is X if and only if tying the gone through part of the knot  does not require threading an end of the cord.
Jarno Suni

jarnos

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Re: Term Post Eye Tiable i.e. PET
« Reply #24 on: February 11, 2021, 11:19:53 PM »
In terms of #1047 Figure 8 eye/loop knot, it is possible to argue that it is 'PET' - because the 'TIB' tying method initially forms a 'bight' - and after the bight is formed, the remainder of the knot is tied. One could postulate that the forming of the initial 'bight' constitutes the beginnings of an 'eye' - with no pre-existing knot in the line. And therefore one could argue that #1047 F8 is 'PET'.

Good point. I guess we could have a better name for such a property.
Jarno Suni