Bike Trip Planning

What this is?

One-file, pure JS + JSON route-planning demo for bike trips using ARC: Answer • Reason • Check.

Data — trips, segments, tags (hilly, no-bike-lane…), observations (rain, wind, construction), preferences.
Policies — declarative JSON rules (if atoms, optional "not": true negations ⇒ then atoms).
Answer — only the newly derived facts (keeps strongest trip priority).
Reason Why — mathematical-English templates with bound variables.
Check — ≥10 JSON assertions against the full fact set.
Trip Plan Summary — per-trip priority & tasks (chooses strongest priority).

Engine: small forward-chainer with unification, subclassing (subClass), transitive partOf, segment→trip observation mapping, and negation-as-failure for "not": true.

Data (JSON)

{
  "classes": ["Trip","Segment","Observation","Hazard","RedFlagHazard","MajorHazard","MinorHazard",
              "RoadClosed","SevereStorm","HeavyRain","StrongHeadwind","Construction","LowLight","Traffic",
              "Tag","Hilly","Sheltered","NoBikeLane","Unlit",
              "Task","Priority","Blocked","Replan","Caution","Go"],

"subclassOf": [
    ["RoadClosed","RedFlagHazard"],
    ["SevereStorm","RedFlagHazard"],
    ["HeavyRain","MajorHazard"],
    ["StrongHeadwind","MajorHazard"],
    ["Construction","MajorHazard"],
    ["LowLight","MinorHazard"],
    ["Traffic","MinorHazard"],
    ["RedFlagHazard","Hazard"],
    ["MajorHazard","Hazard"],
    ["MinorHazard","Hazard"]
  ],

"assets": {
    "T1": {"type":"Trip"},
    "SG1": {"type":"Segment","partOf":"T1"},
    "SG2": {"type":"Segment","partOf":"T1"},

"T2": {"type":"Trip"},
    "SG3": {"type":"Segment","partOf":"T2"}
  },

"segmentTags": [
    ["SG1","Sheltered"],
    ["SG2","Hilly"],
    ["SG2","Unlit"],
    ["SG3","NoBikeLane"]
  ],

"preferences": [
    ["T1","AvoidHills"],
    ["T2","PreferProtectedLanes"]
  ],

"observations": [
    {"id":"ObsRain1","type":"HeavyRain","about":"SG1"},
    {"id":"ObsWind2","type":"StrongHeadwind","about":"SG2"},
    {"id":"ObsLowLight2","type":"LowLight","about":"SG2"},
    {"id":"ObsConstr3","type":"Construction","about":"SG3"},
    {"id":"ObsClosed3","type":"RoadClosed","about":"SG3"}
  ]
}

Policies (declarative JSON rules)

[
  {
    "id":"R1-Subclass",
    "if":[{"pred":"subClass","s":"?A","o":"?B"},{"pred":"isA","s":"?S","o":"?A"}],
    "then":[{"pred":"isA","s":"?S","o":"?B"}],
    "explain":"Since ?A ⊑ ?B and ?S ∈ ?A, infer ?S ∈ ?B."
  },
  {
    "id":"R2-PartOfTransitive",
    "if":[{"pred":"partOf","s":"?x","o":"?y"},{"pred":"partOf","s":"?y","o":"?z"}],
    "then":[{"pred":"partOf","s":"?x","o":"?z"}],
    "explain":"Because ?x is part of ?y and ?y is part of ?z, by transitivity ?x is part of ?z."
  },
  {
    "id":"R3-ObsToTrip",
    "if":[{"pred":"about","s":"?obs","o":"?seg"},{"pred":"partOf","s":"?seg","o":"?T"}],
    "then":[{"pred":"aboutTrip","s":"?obs","o":"?T"}],
    "explain":"Observation ?obs concerns segment ?seg of trip ?T; therefore ?obs is about trip ?T."
  },
  {
    "id":"R4-TagFacts",
    "if":[{"pred":"tag","s":"?S","o":"?Tag"}],
    "then":[{"pred":"hasTag","s":"?S","o":"?Tag"}],
    "explain":"Expose segment tag ?Tag on ?S as a fact."
  },

{ "id":"H-RoadClosed",
    "if":[{"pred":"isA","s":"?obs","o":"RoadClosed"},{"pred":"aboutTrip","s":"?obs","o":"?T"}],
    "then":[{"pred":"requiresTask","s":"?T","o":"Reroute"},{"pred":"requiresTask","s":"?T","o":"AvoidRoad"},{"pred":"priority","s":"?T","o":"Blocked"}],
    "explain":"Road closure on ?T requires rerouting and sets priority Blocked."
  },
  { "id":"H-SevereStorm",
    "if":[{"pred":"isA","s":"?obs","o":"SevereStorm"},{"pred":"aboutTrip","s":"?obs","o":"?T"}],
    "then":[{"pred":"requiresTask","s":"?T","o":"AdjustStartTime"},{"pred":"requiresTask","s":"?T","o":"PackRainGear"},{"pred":"priority","s":"?T","o":"Replan"}],
    "explain":"Severe storm on ?T requires re-planning."
  },
  { "id":"H-HeavyRain",
    "if":[{"pred":"isA","s":"?obs","o":"HeavyRain"},{"pred":"aboutTrip","s":"?obs","o":"?T"}],
    "then":[{"pred":"requiresTask","s":"?T","o":"PackRainGear"},{"pred":"requiresTask","s":"?T","o":"ChooseShelteredPath"}],
    "explain":"Heavy rain on ?T implies rain gear and a sheltered path."
  },
  { "id":"H-StrongHeadwind",
    "if":[{"pred":"isA","s":"?obs","o":"StrongHeadwind"},{"pred":"aboutTrip","s":"?obs","o":"?T"}],
    "then":[{"pred":"requiresTask","s":"?T","o":"AdjustStartTime"},{"pred":"requiresTask","s":"?T","o":"ChooseShelteredPath"}],
    "explain":"Strong headwind on ?T implies timing adjustment and a sheltered path."
  },
  { "id":"H-Construction",
    "if":[{"pred":"isA","s":"?obs","o":"Construction"},{"pred":"aboutTrip","s":"?obs","o":"?T"}],
    "then":[{"pred":"requiresTask","s":"?T","o":"Reroute"}],
    "explain":"Construction on ?T may require a minor reroute."
  },
  { "id":"H-LowLight",
    "if":[{"pred":"isA","s":"?obs","o":"LowLight"},{"pred":"aboutTrip","s":"?obs","o":"?T"}],
    "then":[{"pred":"requiresTask","s":"?T","o":"AddLights"}],
    "explain":"Low light on ?T implies using lights."
  },

{ "id":"P-RedFlag→Replan",
    "if":[{"pred":"isA","s":"?obs","o":"RedFlagHazard"},{"pred":"aboutTrip","s":"?obs","o":"?T"},{"not":true,"pred":"isA","s":"?obs","o":"RoadClosed"}],
    "then":[{"pred":"priority","s":"?T","o":"Replan"}],
    "explain":"Any red-flag hazard (except RoadClosed, which is Blocked) sets priority Replan."
  },
  { "id":"P-Major-NotRed",
    "if":[{"pred":"isA","s":"?obs","o":"MajorHazard"},{"pred":"aboutTrip","s":"?obs","o":"?T"},{"not":true,"pred":"isA","s":"?obs","o":"RedFlagHazard"}],
    "then":[{"pred":"priority","s":"?T","o":"Caution"}],
    "explain":"A major (but not red-flag) hazard on ?T implies priority Caution."
  },
  { "id":"P-Minor-Only",
    "if":[{"pred":"isA","s":"?obs","o":"MinorHazard"},{"pred":"aboutTrip","s":"?obs","o":"?T"},
          {"not":true,"pred":"isA","s":"?any","o":"MajorHazard"},
          {"not":true,"pred":"isA","s":"?any2","o":"RedFlagHazard"}],
    "then":[{"pred":"priority","s":"?T","o":"Caution"}],
    "explain":"Only minor hazards on ?T imply priority Caution."
  },
  { "id":"P-Default-Go",
    "if":[{"pred":"requiresTask","s":"?T","o":"?X"},{"not":true,"pred":"priority","s":"?T","o":"?Any"}],
    "then":[{"pred":"priority","s":"?T","o":"Go"}],
    "explain":"If ?T has tasks but no priority, default to Go."
  },

{ "id":"Pref-AvoidHills",
    "if":[{"pred":"prefers","s":"?T","o":"AvoidHills"},{"pred":"hasTag","s":"?S","o":"Hilly"},{"pred":"partOf","s":"?S","o":"?T"}],
    "then":[{"pred":"requiresTask","s":"?T","o":"UseLowGradientRoute"}],
    "explain":"Trip ?T prefers to avoid hills; since segment ?S is hilly, use a low-gradient route."
  },
  { "id":"Pref-ProtectedLanes",
    "if":[{"pred":"prefers","s":"?T","o":"PreferProtectedLanes"},{"pred":"hasTag","s":"?S","o":"NoBikeLane"},{"pred":"partOf","s":"?S","o":"?T"}],
    "then":[{"pred":"requiresTask","s":"?T","o":"UseProtectedLaneRoute"}],
    "explain":"Trip ?T prefers protected lanes; since segment ?S lacks bike lanes, choose protected lanes."
  }
]

Checks (JSON)

[
  {"name":"ObsRain1 about T1",           "pattern":{"pred":"aboutTrip","s":"ObsRain1","o":"T1"}},
  {"name":"ObsWind2 about T1",           "pattern":{"pred":"aboutTrip","s":"ObsWind2","o":"T1"}},
  {"name":"ObsLowLight2 about T1",       "pattern":{"pred":"aboutTrip","s":"ObsLowLight2","o":"T1"}},
  {"name":"ObsConstr3 about T2",         "pattern":{"pred":"aboutTrip","s":"ObsConstr3","o":"T2"}},
  {"name":"ObsClosed3 about T2",         "pattern":{"pred":"aboutTrip","s":"ObsClosed3","o":"T2"}},

{"name":"T1 requires PackRainGear",    "pattern":{"pred":"requiresTask","s":"T1","o":"PackRainGear"}},
  {"name":"T1 requires ChooseSheltered", "pattern":{"pred":"requiresTask","s":"T1","o":"ChooseShelteredPath"}},
  {"name":"T1 requires AdjustStartTime", "pattern":{"pred":"requiresTask","s":"T1","o":"AdjustStartTime"}},
  {"name":"T1 requires AddLights",       "pattern":{"pred":"requiresTask","s":"T1","o":"AddLights"}},

{"name":"T2 requires Reroute",         "pattern":{"pred":"requiresTask","s":"T2","o":"Reroute"}},
  {"name":"T2 requires AvoidRoad",       "pattern":{"pred":"requiresTask","s":"T2","o":"AvoidRoad"}},
  {"name":"T2 requires UseProtectedLane","pattern":{"pred":"requiresTask","s":"T2","o":"UseProtectedLaneRoute"}},
  {"name":"T1 requires LowGradient",     "pattern":{"pred":"requiresTask","s":"T1","o":"UseLowGradientRoute"}},

{"name":"T1 priority Caution",         "pattern":{"pred":"priority","s":"T1","o":"Caution"}},
  {"name":"T2 priority Blocked",         "pattern":{"pred":"priority","s":"T2","o":"Blocked"}}
]

Controls

Answer (newly derived facts)

computing…

Reason Why (mathematical English)

(click “Run ARC”)

Check

computing…

Trip Plan Summary

(run to populate)