Life In 19x19

And one can construct a ko where the fight is about whether another ko would be a disturbing of fighting ko. I don't know how Ing would have classified that ko.

RobertJasiek wrote:WRT Ing ko rules, the problem is not whether they are dead or alive but whether they are a fighting or disturbing ko.

Before Ing '96, that was so. Life and death were decided by play, and ko play was decided by whether a ko was fighting or disturbing. But with Ing '96, life and death are decided by breath type, and if the life or death of stones involved in a ko is settled, the ko is disturbing. If life or death is unsettled, the ko is fighting. Life and death come first in the logic of the Ing '96 rules.

Matti wrote:And one can construct a ko where the fight is about whether another ko would be a disturbing of fighting ko. I don't know how Ing would have classified that ko.

Well, he no longer has a say in the matter.

Also 1991 rules have breath types.

RobertJasiek wrote:Also 1991 rules have breath types.

Yes, and as far as I can tell, they make the same judgement of life and death and fighting and disturbing kos. But the '91 rules claim as their first principle:

Ing 91 Rules wrote:(1) Life and death of stones must be determined by removal, counting both stones and spaces as territory, and not by special rulings.

Emphasis mine.

Later, in the rule about removal, they do state:

Ing 91 Rules wrote:Article 2: Removal
Breathless stones are removed. Determine life and death by identifying breath types.

Emphasis mine.

As I and others have pointed out, there is a circularity of reasoning about life and death there.

The Ing '96 rules demote removal. There is no article about removal, nor do they state that life and death are determined by removal. The relevant rule is about life and death:

Ing 96 rules wrote:Rule No. 4 － Life and Death
Life and death are determined by breath type; verify by removal.

Emphasis mine.

Verification is ambiguous enough that it can be considered a consistency check, thus avoiding circular reasoning. The following file illustrates the point.

Currently I lack time for a liguistic analysis of the 1996 rules. However, I disagree with the following.

You say that, in a quadruple ko initially with each non-single-stone string having exactly two breaths, WLOG the white string is said by the rules to have two REAL breaths. You conclude that the string is alive. Before making this conclusion, how can you assess that the breaths are real? ATM I do not have the 1996 booklet in my hands so I do not know if there is a precedental declaration for this quadruple ko. Supposing there is not. Real breaths are not something given a priori because one needs to distinguish them from unreal breaths. We cannot presume "alive" because of vicious circle. The only suitable means is by the possibility of forcing removal presuming some ruleset for constructing sequences. (And not just your one sequence shown.) However, you say that verification [of removal] was ambiguous enough that it can be considered a consistency check. No, it cannot be only a consistency check. It is the necessary means, also to avoid circuluar reasoning. This is so regardless of the specific example and the linguistic demotion in the central rule in its English version from "determined by" to "verified by". I recall that in a text about the 1996 rules (do not recall if it was the booklet or a different Ing pamphlet) the necessity of assessment by removal is described.

RobertJasiek wrote:Currently I lack time for a liguistic analysis of the 1996 rules. However, I disagree with the following.

You say that, in a quadruple ko initially with each non-single-stone string having exactly two breaths, WLOG the white string is said by the rules to have two REAL breaths. You conclude that the string is alive. Before making this conclusion, how can you assess that the breaths are real?

Ing '96, Rule 4: Life and Death; Breath types, states:

All internal breaths are real breaths with a minimum of two real breaths for a live group:

RobertJasiek wrote:ATM I do not have the 1996 booklet in my hands so I do not know if there is a precedental declaration for this quadruple ko. Supposing there is not. Real breaths are not something given a priori because one needs to distinguish them from unreal breaths. We cannot presume "alive" because of vicious circle. The only suitable means is by the possibility of forcing removal presuming some ruleset for constructing sequences.

Requiring life and death to be determined by removal alone, as earlier versions of the Ing rules did, leads to circular reasoning. That is why, I believe, Ing quietly dropped that principle from the '96 rules, whereas it is the first principle of the '91 rules.

Bill Spight wrote: Ing '96, Rule 4: Life and Death; Breath types, states:

All internal breaths are real breaths with a minimum of two real breaths for a live group:

This just shifts the problem from "what is real" to "what is internal".

Requiring life and death to be determined by removal alone, as earlier versions of the Ing rules did, leads to circular reasoning.

This is so in Ing rules but it need not be so because one can start with the Default Restriction Rules, hypothetical-sequences, hypothetical-strategies and "force" to derive higher level concepts, such as life, death, ko, internal:

http://home.snafu.de/jasiek/j2003.html
http://home.snafu.de/jasiek/ko.pdf
http://home.snafu.de/jasiek/ko_types.pdf
http://home.snafu.de/jasiek/external.pdf

Of course, this was beyond the capabilities of Ing and the Ing foundation people.

E.g., using the aforementioned techniques, one can first define alive, ko-string and non-ko-string (each string that is not a ko-string) and define: A "real breath" of a non-ko-string is an adjacent breath if the non-ko-string is alive. Similarly, all those other ca. 50 (superfluous) Ing terms can be defined with some more effort.

EDITED.

RobertJasiek wrote:

Bill Spight wrote: Ing '96, Rule 4: Life and Death; Breath types, states:

All internal breaths are real breaths with a minimum of two real breaths for a live group:

This just shifts the problem from "what is real" to "what is internal".

Requiring life and death to be determined by removal alone, as earlier versions of the Ing rules did, leads to circular reasoning.

This is so in Ing rules but it need not be so

Indeed.