Clause Edge is an Edge type that expresses logical and discourse relations between predications (Verb Edge), events (Event6 Edge), relationships (Triple Edge), or other Clauses.

It is designed based on the discourse relations of RST (Rhetorical Structure Theory).

Packet Structure (4 words, 64 bits)

1st WORD (16 bits):
┌─────────────────────┬────────────┬────────┐
│      Prefix         │  RelType   │Reserved│
│       10 bits       │   4 bits   │ 2 bits │
└─────────────────────┴────────────┴────────┘
 [1100 000 010]        [RRRR]       [xx]

2nd WORD: Edge TID (16 bits)
3rd WORD: TID 1 (16 bits) - First clause
4th WORD: TID 2 (16 bits) - Second clause
FieldBitsDescription
Prefix101100 000 010
RelType416 RST relations
Reserved2For future extension
Edge TID16Unique identifier for this Edge
TID 116First clause reference
TID 216Second clause reference

Relation Types (4 bits = 16)

Causal Relations

CodeTypeDescriptionExample
0000CAUSECause → Effect“It rained, so I stayed home”
0001RESULTEffect ← Cause“I stayed home, because it rained”
0010CONDITIONCondition → Consequence“If it rains, I won’t go”
0011PURPOSEPurpose“We eat to live”

Temporal/Sequential Relations

CodeTypeDescriptionExample
0100SEQUENCEChronological“Had dinner, then slept”
0101PARALLELSimultaneous/parallel“Spoke while smiling”

Contrast/Concession Relations

CodeTypeDescriptionExample
0110CONTRASTContrast“A is big and B is small”
0111CONCESSIONConcession“Although it was hard, I did it”

Elaboration/Background Relations

CodeTypeDescriptionExample
1000ELABORATIONElaboration“Specifically speaking”
1001BACKGROUNDBackground info“For reference, the situation at that time was”

Argumentation Relations

CodeTypeDescriptionExample
1010EVIDENCEEvidence presentation“Because… that is why”
1011EVALUATIONEvaluation“This is good/bad”

Other Relations

CodeTypeDescriptionExample
1100SOLUTIONHOODProblem → Solution“The problem is X, the solution is Y”
1101ALTERNATIVEChoice/alternative“Go or not go”
1110MEANSMeans“Achieved it by doing this”
1111RESERVEDReservedFor future extension

TID Ordering Rules

Direction is determined by TID order.

RelationTID 1TID 2
CAUSECauseEffect
RESULTEffectCause
CONDITIONConditionConsequence
PURPOSEActionPurpose
SEQUENCEPrecedingFollowing
EVIDENCEEvidenceClaim
ELABORATIONCoreElaboration

Multinuclear vs Nucleus-Satellite

Follows the RST distinction.

Nucleus-Satellite (Asymmetric)

RelationTID 1TID 2
CAUSECause (Satellite)Effect (Nucleus)
CONDITIONCondition (Satellite)Consequence (Nucleus)
EVIDENCEEvidence (Satellite)Claim (Nucleus)
ELABORATIONCore (Nucleus)Elaboration (Satellite)

Multinuclear (Symmetric)

RelationTID 1TID 2
SEQUENCEPrecedingFollowing
PARALLELFirstSecond
CONTRASTFirstSecond
ALTERNATIVEFirstSecond

In symmetric relations, TID order does not indicate semantic priority.

Examples

Simple causation: “It rained, so I stayed home”

Verb Edge E01: rain(rain) | TID=0x0001
Verb Edge E02: stay(I, home) | TID=0x0002

Clause Edge:
  1st: [1100 000 010] [0000] [00]  - Prefix + CAUSE + Reserved
  2nd: [0x0100]                    - Edge TID
  3rd: [0x0001]                    - TID 1 (cause: E01)
  4th: [0x0002]                    - TID 2 (effect: E02)

Nested Clause: “It rained so I stayed home, and therefore I studied”

Verb Edge E01: rain(rain) | TID=0x0001
Verb Edge E02: stay(I, home) | TID=0x0002
Verb Edge E03: study(I) | TID=0x0003

Clause Edge C01:
  1st: [1100 000 010] [0000] [00]  - Prefix + CAUSE
  2nd: [0x0100]                    - Edge TID
  3rd: [0x0001]                    - E01
  4th: [0x0002]                    - E02

Clause Edge C02:
  1st: [1100 000 010] [0001] [00]  - Prefix + RESULT
  2nd: [0x0101]                    - Edge TID
  3rd: [0x0100]                    - C01 (Clause TID reference!)
  4th: [0x0003]                    - E03

Design Rationale

Why RST-based

  • Over 30 years of accumulated research
  • Validated across diverse corpora
  • Existing discourse parsing tools
  • Language-independent

Why 4 bits (16 types)

  • Covers 12+ core RST relations
  • Preserves room for extension
  • 3 bits (8 types) would be insufficient

Why 4-word simplification

  • Direction: Determined by TID order (no separate bits needed)
  • Confidence: Handled as separate metadata
  • 2 reserved bits: For future extension