DMN — Deliberately Contradictory: Two Rules, One Input
The other teaching artefact. Under UNIQUE, two rules that can both fire is a contradiction rather than a preference — an applicant aged exactly 65 with a clean file matches two rules that disagree about the answer, and the table does not say which wins. Change the hit policy to PRIORITY or FIRST and the same table becomes well defined, which is the lesson.
Make it your own.
title "Premium band — with an overlap (deliberate)"
input Driver "Driver"
decision Band "Premium band"
Driver -> Band
decision Band "Premium band" {
hit U
input Age number [17..90]
input Claims number [0..10]
output Band enum { Standard, Loaded, Referred }
rule [17..25) | [0..10] -> Loaded
rule [25..65] | [0..2) -> Standard
rule [25..65] | [2..10] -> Loaded
rule [65..90] | [0..10] -> Referred // 65 is in this rule AND the two above
}