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:
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.
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'.
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?