Library prosa.classic.model.arrival.basic.arrival_sequence

Require Import prosa.classic.util.all prosa.classic.model.arrival.basic.task prosa.classic.model.time.
From mathcomp Require Import ssreflect ssrbool ssrfun eqtype ssrnat seq fintype bigop.

Module ArrivalSequence.

  Export Time.

  Section ArrivalSequenceDef.

    Variable Job: eqType.

    Definition arrival_sequence := time seq Job.

  End ArrivalSequenceDef.

  Section JobProperties.

    Context {Job: eqType}.
    Variable arr_seq: arrival_sequence Job.

    Definition jobs_arriving_at (t: time) := arr_seq t.

    Definition arrives_at (j: Job) (t: time) := j \in jobs_arriving_at t.

    Definition arrives_in (j: Job) := t, j \in jobs_arriving_at t.

  End JobProperties.

  Section ArrivalSequenceProperties.

    Context {Job: eqType}.
    Variable job_arrival: Job time.

    Variable arr_seq: arrival_sequence Job.

    Definition arrival_times_are_consistent :=
       j t,
        arrives_at arr_seq j t job_arrival j = t.

    Definition arrival_sequence_is_a_set := t, uniq (jobs_arriving_at arr_seq t).

  End ArrivalSequenceProperties.

  Section PropertiesOfArrivalTime.

    Context {Job: eqType}.
    Variable job_arrival: Job time.

    Variable j: Job.

    Definition has_arrived (t: time) := job_arrival j t.

    Definition arrived_before (t: time) := job_arrival j < t.

    Definition arrived_between (t1 t2: time) := t1 job_arrival j < t2.

  End PropertiesOfArrivalTime.

  Section ArrivalSequencePrefix.

    Context {Job: eqType}.
    Variable job_arrival: Job time.

    Variable arr_seq: arrival_sequence Job.

    Definition jobs_arrived_between (t1 t2: time) :=
      \cat_(t1 t < t2) jobs_arriving_at arr_seq t.

    Definition jobs_arrived_up_to (t: time) := jobs_arrived_between 0 t.+1.

    Definition jobs_arrived_before (t: time) := jobs_arrived_between 0 t.

    Section Lemmas.

      Section Basic.

        Lemma job_arrived_between_cat:
           t1 t t2,
            t1 t
            t t2
            jobs_arrived_between t1 t2 = jobs_arrived_between t1 t ++ jobs_arrived_between t t2.

        Lemma jobs_arrived_between_mem_cat:
           j t1 t t2,
            t1 t
            t t2
            j \in jobs_arrived_between t1 t2 =
            (j \in jobs_arrived_between t1 t ++ jobs_arrived_between t t2).

        Lemma jobs_arrived_between_sub:
           j t1 t1' t2 t2',
            t1' t1
            t2 t2'
            j \in jobs_arrived_between t1 t2
            j \in jobs_arrived_between t1' t2'.

      End Basic.

      Section ArrivalTimes.

        Hypothesis H_arrival_times_are_consistent:
          arrival_times_are_consistent job_arrival arr_seq.

        Lemma in_arrivals_implies_arrived:
           j t1 t2,
            j \in jobs_arrived_between t1 t2
            arrives_in arr_seq j.

        Lemma in_arrivals_implies_arrived_between:
           j t1 t2,
            j \in jobs_arrived_between t1 t2
            arrived_between job_arrival j t1 t2.

        Lemma in_arrivals_implies_arrived_before:
           j t,
            j \in jobs_arrived_before t
            arrived_before job_arrival j t.

        Lemma arrived_between_implies_in_arrivals:
           j t1 t2,
            arrives_in arr_seq j
            arrived_between job_arrival j t1 t2
            j \in jobs_arrived_between t1 t2.

        Lemma arrivals_uniq :
          arrival_sequence_is_a_set arr_seq
           t1 t2, uniq (jobs_arrived_between t1 t2).

      End ArrivalTimes.

    End Lemmas.

  End ArrivalSequencePrefix.

End ArrivalSequence.