RobertJasiek wrote:
For the rules, the ideas behind the rules are immaterial. The rules themselves must be clear. The wording must clearly express what their meaning shall be. In this case, state the player explicitly, at least as a pronoun referring to him stated at an earlier place in the rules text.
Same for the ko rules: they ought to be clear. They are unclear if I have to consult Cassandra's examples to reverse-engineer a guessed rules meaning.
I am clearly completly unable to define an immateriel rule.
I tried to begin to read the following one and I gave up very very quickly.
OC wording has to be carefully chosen but do not ask me to write an immaterial rule.
I am quite sure at least 99% of professionnal Go players are unable to read the rule here under. Show such rule to a beginner and you will be sure this potential player will choose another game!
Who amongs the readers of this forum is able to read and UNDERSTAND (!) such rule?
Logical Japanese Rules of Go
(precise version)
A. Game
A1. "Two players play an even game of go on some board according to
Logical Japanese Rules of Go "
by doing - essentially - the following in the given order:
1. Randomly decide which player chooses first and which last.
2. The player choosing first must choose an initial state whose
board is the one in use. This state is called "current state".
3. The player choosing last must choose which player is called
"Black". The other is called "White".
4. While the current state is not final, the player having the
turn in it must replace it with one of its successors.
5. When the current state is final, the player with the higher
score in it wins. If both are equal, it's a "jigo" (tie).
A2. "A state is initial" only if all this holds:
1. Its set of black locations is empty.
2. Its set of white locations is empty.
3. Its set of temporarily marked locations is a subset of its
set of locations. (Includes the case that both are the same.)
4. Its set of permanently marked locations is empty.
5. Its black captive count is a non-negative integer not
greater than the number of members of its set of locations.
6. Its white captive count is 0.
7. Its turn is "black".
8. Its pass count is 0 if its set of temporarily marked
locations is empty, otherwise its pass count is -1.
9. Its history is empty.
(A state's "komi" is its first situation's black captive count
minus its first situation's white captive count, and
a state's "first situation" is the first member of the list
formed by appending its situation to its history.)
A3. "Black has the turn in a state"
only if this state's turn is "black".
A4. "White has the turn in a state"
only if this state's turn is "white".
B. Successor
B1. "State S4 is a successor of state S1"
only if some state S2 and S3 fulfill all this:
1. S1 is not final.
2. a) S1's turn is "black", and
S4 is a white successor of S1; or
b) S1's turn is "white",
S2 is colored reverse to S1,
S3 is a white successor of S2, and
S4 is colored reverse to S3.
B2. "State S4 is a white successor of state S1"
only if some state S2 and S3, text T1 and T2,
integer set K, and integer P fulfill all this:
1. S1's turn is "black".
2. a) S2 is S1, and T1 is "no cycle removed"; or
b) S2 is reachable by removing a cycle in S1,
and T1 is "cycle removed".
3. a) S3 is S2, K is empty, and T2 is "no stone played"; or
b) S3 is reachable by playing a black stone in S2 that
clears set K by ko, and T2 is "stone played".
4. a) T1 is "no cycle removed", T2 is "no stone played",
and P is S1's pass count plus 1; or
b) K is not empty, and P is -1; or
c) K is empty, T1 is "cycle removed" or T2 is "stone played",
and P is 0.
5. S4's history is S1's history with S1's situation appended to it,
S4's set of temporarily marked locations is K,
S4's pass count is P,
S4's turn is "white",
and everything else in S4 is as in S3.
B3. "State S2 is reachable by removing a cycle in state S1"
only if some list of situations H, list of integer sets L,
integer set B and C and D, and integer NB and NW fulfill
all this:
1. S1's pass count isn't 1.
2. H is a trailing sub-list (a suffix) of S1's history,
and H's first member is similar to S1's situation.
(This includes the case that H is S1's history.)
3. L is the list that would result if every member of H
would be replaced by the union of its set of black
locations with its set of white locations.
4. B is the union of all members of L.
5. C is the intersection of all members of L.
6. D is the set of those members of B not member of C.
7. NB is the number of members of the intersection of D
with S1's set of black locations.
8. NW is the number of members of the intersection of D
with S1's set of white locations.
9. S2's black captive count is S1's black captive count plus NB,
S2's white captive count is S1's white captive count plus NW,
S2's set of black locations is the set of those members
of S1's set of black locations not member of D,
S2's set of white locations is the set of those members
of S1's set of white locations not member of D,
S2's set of permanently marked locations is the union
of S1's set of permanently marked locations with D,
and everything else in S2 is as in S1.
B4. "State S3 is reachable by playing a black stone in state S1
that clears integer set K by ko" only if some integer X and
Y and N, state S2, and integer set W fulfill all this:
1. S1's turn is "black".
2. X is member of S1's set of locations, but neither colored
nor marked in S1.
3. S2's set of black locations is S1's set of black locations
extended by X, and everything else in S2 is as in S1.
4. W is the set of all members of S2's set of white locations
that have no liberties in S2.
5. If W is empty, then X has contact to Y in S2 and either
Y is not colored and not permanently marked in S2
or Y is black and permanently marked in S2.
6. N is the number of members of W.
7. S3's set of white locations is the set of those members
of S2's set of white locations not member of W,
S3's white captive count is S2's white captive count plus N,
and everything else in S3 is as in S2.
8. K is W if N is 1 and each neighbor of X in S2 is white in
S2, otherwise K is empty.
C. Score
C1. "Integer N is Black's score in state S1"
only if some integer set L and integer N1 and N2 and N3
fulfill all this:
1. L is the set of those members of S1's set of locations
that Black controls in S1.
2. N1 is the number of members of L that aren't black in S1.
3. N2 is the number of members of L that are white in S1.
4. N3 is S1's white captive count.
5. N is the sum of N1, N2, and N3.
C2. "Integer N is White's score in state S1"
only if some state S2 fulfills all this:
1. S2 is colored reverse to S1.
2. N is Black's score in S2.
C3. "Black controls integer X in state S1"
only if some integer set L fulfills all this:
1. X is member of L.
2. Black can lock L in S1.
C4. "Black can lock integer set L in state S1"
only if some state S2 fulfills all this:
1. L is bordered by Black in S1.
2. S2 is Black's worst case for L in S1.
3. White can't prevent a black 2-eye formation on L in S2.
C5. "Integer set L is bordered by Black in state S1"
only if all this holds:
1. L is a subset of S1's set of locations (this includes the
case that both are the same), and
2. for every member X of L that is neighbor of a Y not member
of L all this holds:
1. X is black in S1, and
2. Y is not black in S1
C6. "State S3 is Black's worst case for integer set L1 in state S1"
only if some integer set L2 and state S2 fulfill all this:
1. S1's set of locations is the union of L1 with L2.
2. S2's history is empty,
S2's set of temporarily marked locations is empty,
S2's black captive count is 0,
S2's white captive count is 0,
S2's pass count is 0,
S2's turn is "white,
S2's set of black locations is the intersection
of S1's set of black locations with L1,
S2's set of white locations is the union
of S1's set of white locations with L2,
S2's set of permanently marked locations is the union
of S1's set of permanently marked locations with L2,
and everything else in S2 is as in S1.
3. S3's set of black locations is the set of those members
of S2's set of black locations that have liberties in S2,
and everything else in S3 is as in S2.
C7. "White can't prevent a black 2-eye formation on integer set L
in state S1" only if at least one holds:
1. Black has build a 2-eye formation on L in S1; or
2. S1's turn is "black",
S1's situation is not final,
S1's situation is not similar to a member of S1's history,
and at least one successor S2 of S1 has the property that
White can't prevent a black 2-eye formation on L in S2; or
3. S1's turn is "white",
S1's situation is not final,
S1's situation is not similar to a member of S1's history,
and each successor S2 of S1 has the property that
White can't prevent a black 2-eye formation on L in S2.
C8. "Black has build a 2-eye formation on integer set L in state S1"
only if all this holds:
1. L is not empty.
2. L shares no member with S1's set of white locations.
3. L is bordered by Black in S1.
4. Every member of L is member of at least one member of
S1's neighbor relation.
5. Every member of S1's neighbor relation that's subset of L
shares at least one member with S1's set of black locations.
6. Every member of L that is colored in S1 has contact to
at least two (different) members of L in S1 which both
are not colored in S1.
D. Contact
D1. "Integer X has liberties in state S1"
only if at least one holds:
1. X is colored and permanently marked in S1. Or
2. X has contact to some Y in S1; and either
a) Y is not colored in S1, or
b) Y has the same color as X in S1 and
Y is permanently marked in S1.
D2. "Integer X has contact to integer Y in state S1"
only if X has contact to Y in state S1 avoiding V,
and V is the set whose only member is X.
("contact" neither is symmetric, reflexive, nor transitive.)
D3. "Integer X has contact to integer Y in state S1 avoiding
integer set V1" only if some integer Z and integer set V2
fulfill at least one:
1. X is neighbor of Y in S1; or
2. Z is neighbor of X in S1,
Z has the same color as X in S1,
Z is not member of V1,
V2 is V1 extended by Z, and
Z has contact to Y in S1 avoiding V2.
D4. "Integer X is neighbor of integer Y in state S1"
only if the set whose only members are X and Y is member
of S1's neighbor relation.
("neighbor" is symmetric, but neither reflexive nor transitive.)
D5. "Integer X is black in state S1"
only if X is member of S1's set of black locations.
D6. "Integer X is white in state S1"
only if X is member of S1's set of white locations.
D7. "Integer X is marked temporarily in state S1"
only if X is member of S1's set of temporarily marked locations.
D8. "Integer X is marked permanently in state S1"
only if X is member of S1's set of permanently marked locations.
D9. "Integer X is colored in state S1" only if at least one holds:
1. X is black in S1, or
2. X is white in S1.
D10."Integer X is marked in state S1" only if at least one holds:
1. X is marked temporarily in S1, or
2. X is marked permanently in S1.
D11."Integer X has the same color as integer Y in state S1"
only if all this holds:
1. X is black in S1 only if Y is black in S1, and
2. X is white in S1 only if Y is white in S1.
E. State
E1. "A state is final" only if its situation is final.
E2. "A situation is final" only if its pass count is 2.
E3. "Two situations are similar" only if either
1. they are the same, or
2. they are not the same, but only differ in their
captive counts.
E4. "State S2 is colored reverse to state S1"
only if some text T fulfills all this:
1. a) T is "black" and S1's turn is "white", or
b) T is "white" and S1's turn is "black".
2. S2's set of black locations is S1's set of white locations,
S2's set of white locations is S1's set of black locations,
S2's black captive count is S1's white captive count,
S2's white captive count is S1's black captive count,
S2's turn is T,
and everything else in S2 is as in S1.
E5. A "state" consists of exactly 3 parts of the given
names and sorts:
1. its "board" - a board
2. its "situation" - a situation
3. its "history" - a list of situations
The first two parts again consist of named parts - subparts of
the state. Since all these subparts have unique names, it's save
to omit the part name when referring to a state's subpart.
(For example, "the state's set of black locations" is short
for "the state's situation's set of black locations".)
E6. A "board" consists of exactly 2 parts of the given
names and sorts:
1. its "set of locations" - a finite integer set
2. its "neighbor relation" - a set of unordered pairs,
where each such pair is a set containing exactly two
(different) members of the board's set of locations
E7. A "situation" consists of exactly 8 parts of the given
names and sorts:
1. its "set of black locations" - an integer set
2. its "set of white locations" - an integer set
3. its "set of temporarily marked locations" - an integer set
4. its "set of permanently marked locations" - an integer set
5. its "black captive count" - a non-negative integer
6. its "white captive count" - a non-negative integer
7. its "turn" - either the text "black" or "white"
8. its "pass count" - either the integer -1, 0, 1, or 2