Changes from 0.5
disl0.60.6Changes from 0.5
Contents of DISL 0.6
DISL 0.6 (draft, 2026-10-22) adds no construct. It settles what 0.5 left open about a relation type's flags, ruled by the maintainer on 2026-10-22 with the answers to Q1 to Q3 of spec 034-disl-relation-flag-inheritance and the decision "Approve, all hosts". Every valid 0.5 specification that neither widens a flag nor inherits two different values of one is a valid 0.6 specification, with the meaning of the inheriting reading.
| # | Change | 0.5 said | 0.6 says | Reason | Section |
|---|---|---|---|---|---|
| 1 | A flag a relation type does not state | Nothing; read as inherited by some hosts and as the default by others. | Inherited along the C3 linearisation, else the 4.9 default. | One specification was two tools, depending on the host. | 4.7, 4.9 |
| 2 | A flag a subtype states differently | Nothing. | Only narrowing; widening, or a different directed, is an error. |
A subtype is accepted wherever its supertype is. | 4.7 |
| 3 | Supertypes whose flags differ | Nothing. | An error unless the subtype states the flag. | As for conflicting inherited attributes. | 4.7 |
DISL 0.6 needs no change to DID, DESL or FBL. The worked example service-calls.dis shows the rule, and the specifications in refused/ show what a validator refuses.