/**
* This library is used in the QL detective tutorials.
*
* Note: Data is usually stored in a separate database and the QL libraries only contain predicates,
* but for this tutorial both the data and the predicates are stored in the library.
*/
/**
* A person known to the QL detective tutorials, represented by a string
* (their first name).
*/
class Person extends string {
Person() {
this =
[
"Ronil", "Dina", "Ravi", "Bruce", "Jo", "Aida", "Esme", "Charlie", "Fred", "Meera", "Maya",
"Chad", "Tiana", "Laura", "George", "Will", "Mary", "Almira", "Susannah", "Rhoda",
"Cynthia", "Eunice", "Olive", "Virginia", "Angeline", "Helen", "Cornelia", "Harriet",
"Mahala", "Abby", "Margaret", "Deb", "Minerva", "Severus", "Lavina", "Adeline", "Cath",
"Elisa", "Lucretia", "Anne", "Eleanor", "Joanna", "Adam", "Agnes", "Rosanna", "Clara",
"Melissa", "Amy", "Isabel", "Jemima", "Cordelia", "Melinda", "Delila", "Jeremiah", "Elijah",
"Hester", "Walter", "Oliver", "Hugh", "Aaron", "Reuben", "Eli", "Amos", "Augustus",
"Theodore", "Ira", "Timothy", "Cyrus", "Horace", "Simon", "Asa", "Frank", "Nelson",
"Leonard", "Harrison", "Anthony", "Louis", "Milton", "Noah", "Cornelius", "Abdul", "Warren",
"Harvey", "Dennis", "Wesley", "Sylvester", "Gilbert", "Sullivan", "Edmund", "Wilson",
"Perry", "Matthew", "Simba", "Nala", "Rafiki", "Shenzi", "Ernest", "Gertrude", "Oscar",
"Lilian", "Raymond", "Elgar", "Elmer", "Herbert", "Maude", "Mae", "Otto", "Edwin",
"Ophelia", "Parsley", "Sage", "Rosemary", "Thyme", "Garfunkel", "King Basil", "Stephen"
]
}
/** Gets the hair color of the person. If the person is bald, there is no result. */
string getHairColor() {
this = "Ronil" and result = "black"
or
this = "Dina" and result = "black"
or
this = "Ravi" and result = "black"
or
this = "Bruce" and result = "brown"
or
this = "Jo" and result = "red"
or
this = "Aida" and result = "blond"
or
this = "Esme" and result = "blond"
or
this = "Fred" and result = "gray"
or
this = "Meera" and result = "brown"
or
this = "Maya" and result = "brown"
or
this = "Chad" and result = "brown"
or
this = "Tiana" and result = "black"
or
this = "Laura" and result = "blond"
or
this = "George" and result = "blond"
or
this = "Will" and result = "blond"
or
this = "Mary" and result = "blond"
or
this = "Almira" and result = "black"
or
this = "Susannah" and result = "blond"
or
this = "Rhoda" and result = "blond"
or
this = "Cynthia" and result = "gray"
or
this = "Eunice" and result = "white"
or
this = "Olive" and result = "brown"
or
this = "Virginia" and result = "brown"
or
this = "Angeline" and result = "red"
or
this = "Helen" and result = "white"
or
this = "Cornelia" and result = "gray"
or
this = "Harriet" and result = "white"
or
this = "Mahala" and result = "black"
or
this = "Abby" and result = "red"
or
this = "Margaret" and result = "brown"
or
this = "Deb" and result = "brown"
or
this = "Minerva" and result = "brown"
or
this = "Severus" and result = "black"
or
this = "Lavina" and result = "brown"
or
this = "Adeline" and result = "brown"
or
this = "Cath" and result = "brown"
or
this = "Elisa" and result = "brown"
or
this = "Lucretia" and result = "gray"
or
this = "Anne" and result = "black"
or
this = "Eleanor" and result = "brown"
or
this = "Joanna" and result = "brown"
or
this = "Adam" and result = "black"
or
this = "Agnes" and result = "black"
or
this = "Rosanna" and result = "gray"
or
this = "Clara" and result = "blond"
or
this = "Melissa" and result = "brown"
or
this = "Amy" and result = "brown"
or
this = "Isabel" and result = "black"
or
this = "Jemima" and result = "red"
or
this = "Cordelia" and result = "red"
or
this = "Melinda" and result = "gray"
or
this = "Delila" and result = "white"
or
this = "Jeremiah" and result = "gray"
or
this = "Hester" and result = "black"
or
this = "Walter" and result = "black"
or
this = "Aaron" and result = "gray"
or
this = "Reuben" and result = "gray"
or
this = "Eli" and result = "gray"
or
this = "Amos" and result = "white"
or
this = "Augustus" and result = "white"
or
this = "Theodore" and result = "white"
or
this = "Timothy" and result = "brown"
or
this = "Cyrus" and result = "brown"
or
this = "Horace" and result = "brown"
or
this = "Simon" and result = "brown"
or
this = "Asa" and result = "brown"
or
this = "Frank" and result = "brown"
or
this = "Nelson" and result = "black"
or
this = "Leonard" and result = "black"
or
this = "Harrison" and result = "black"
or
this = "Anthony" and result = "black"
or
this = "Louis" and result = "black"
or
this = "Milton" and result = "blond"
or
this = "Noah" and result = "blond"
or
this = "Cornelius" and result = "red"
or
this = "Abdul" and result = "brown"
or
this = "Warren" and result = "red"
or
this = "Harvey" and result = "blond"
or
this = "Dennis" and result = "blond"
or
this = "Wesley" and result = "brown"
or
this = "Sylvester" and result = "brown"
or
this = "Gilbert" and result = "brown"
or
this = "Sullivan" and result = "brown"
or
this = "Edmund" and result = "brown"
or
this = "Wilson" and result = "blond"
or
this = "Perry" and result = "black"
or
this = "Simba" and result = "brown"
or
this = "Nala" and result = "brown"
or
this = "Rafiki" and result = "red"
or
this = "Shenzi" and result = "gray"
or
this = "Ernest" and result = "blond"
or
this = "Gertrude" and result = "brown"
or
this = "Oscar" and result = "blond"
or
this = "Lilian" and result = "brown"
or
this = "Raymond" and result = "brown"
or
this = "Elgar" and result = "brown"
or
this = "Elmer" and result = "brown"
or
this = "Herbert" and result = "brown"
or
this = "Maude" and result = "brown"
or
this = "Mae" and result = "brown"
or
this = "Otto" and result = "black"
or
this = "Edwin" and result = "black"
or
this = "Ophelia" and result = "brown"
or
this = "Parsley" and result = "brown"
or
this = "Sage" and result = "brown"
or
this = "Rosemary" and result = "brown"
or
this = "Thyme" and result = "brown"
or
this = "Garfunkel" and result = "brown"
or
this = "King Basil" and result = "brown"
or
this = "Stephen" and result = "black"
or
this = "Stephen" and result = "gray"
}
/** Gets the age of the person (in years). If the person is deceased, there is no result. */
int getAge() {
this = "Ronil" and result = 21
or
this = "Dina" and result = 53
or
this = "Ravi" and result = 16
or
this = "Bruce" and result = 35
or
this = "Jo" and result = 47
or
this = "Aida" and result = 26
or
this = "Esme" and result = 25
or
this = "Charlie" and result = 31
or
this = "Fred" and result = 68
or
this = "Meera" and result = 62
or
this = "Maya" and result = 29
or
this = "Chad" and result = 49
or
this = "Tiana" and result = 18
or
this = "Laura" and result = 2
or
this = "George" and result = 3
or
this = "Will" and result = 41
or
this = "Mary" and result = 51
or
this = "Almira" and result = 1
or
this = "Susannah" and result = 97
or
this = "Rhoda" and result = 39
or
this = "Cynthia" and result = 89
or
this = "Eunice" and result = 83
or
this = "Olive" and result = 25
or
this = "Virginia" and result = 52
or
this = "Angeline" and result = 22
or
this = "Helen" and result = 79
or
this = "Cornelia" and result = 59
or
this = "Harriet" and result = 57
or
this = "Mahala" and result = 61
or
this = "Abby" and result = 24
or
this = "Margaret" and result = 59
or
this = "Deb" and result = 31
or
this = "Minerva" and result = 72
or
this = "Severus" and result = 61
or
this = "Lavina" and result = 33
or
this = "Adeline" and result = 17
or
this = "Cath" and result = 22
or
this = "Elisa" and result = 9
or
this = "Lucretia" and result = 56
or
this = "Anne" and result = 11
or
this = "Eleanor" and result = 80
or
this = "Joanna" and result = 43
or
this = "Adam" and result = 37
or
this = "Agnes" and result = 47
or
this = "Rosanna" and result = 61
or
this = "Clara" and result = 31
or
this = "Melissa" and result = 37
or
this = "Amy" and result = 12
or
this = "Isabel" and result = 6
or
this = "Jemima" and result = 16
or
this = "Cordelia" and result = 21
or
this = "Melinda" and result = 55
or
this = "Delila" and result = 66
or
this = "Jeremiah" and result = 54
or
this = "Elijah" and result = 42
or
this = "Hester" and result = 68
or
this = "Walter" and result = 66
or
this = "Oliver" and result = 33
or
this = "Hugh" and result = 51
or
this = "Aaron" and result = 49
or
this = "Reuben" and result = 58
or
this = "Eli" and result = 70
or
this = "Amos" and result = 65
or
this = "Augustus" and result = 56
or
this = "Theodore" and result = 69
or
this = "Ira" and result = 1
or
this = "Timothy" and result = 54
or
this = "Cyrus" and result = 78
or
this = "Horace" and result = 34
or
this = "Simon" and result = 23
or
this = "Asa" and result = 28
or
this = "Frank" and result = 59
or
this = "Nelson" and result = 38
or
this = "Leonard" and result = 58
or
this = "Harrison" and result = 7
or
this = "Anthony" and result = 2
or
this = "Louis" and result = 34
or
this = "Milton" and result = 36
or
this = "Noah" and result = 48
or
this = "Cornelius" and result = 41
or
this = "Abdul" and result = 67
or
this = "Warren" and result = 47
or
this = "Harvey" and result = 31
or
this = "Dennis" and result = 39
or
this = "Wesley" and result = 13
or
this = "Sylvester" and result = 19
or
this = "Gilbert" and result = 16
or
this = "Sullivan" and result = 17
or
this = "Edmund" and result = 29
or
this = "Wilson" and result = 27
or
this = "Perry" and result = 31
or
this = "Matthew" and result = 55
or
this = "Simba" and result = 8
or
this = "Nala" and result = 7
or
this = "Rafiki" and result = 76
or
this = "Shenzi" and result = 67
}
/** Gets the height of the person (in cm). If the person is deceased, there is no result. */
float getHeight() {
this = "Ronil" and result = 183.0
or
this = "Dina" and result = 155.1
or
this = "Ravi" and result = 175.2
or
this = "Bruce" and result = 191.3
or
this = "Jo" and result = 163.4
or
this = "Aida" and result = 182.6
or
this = "Esme" and result = 176.9
or
this = "Charlie" and result = 189.7
or
this = "Fred" and result = 179.4
or
this = "Meera" and result = 160.1
or
this = "Maya" and result = 153.0
or
this = "Chad" and result = 168.5
or
this = "Tiana" and result = 149.7
or
this = "Laura" and result = 87.5
or
this = "George" and result = 96.4
or
this = "Will" and result = 167.1
or
this = "Mary" and result = 159.8
or
this = "Almira" and result = 62.1
or
this = "Susannah" and result = 145.8
or
this = "Rhoda" and result = 180.1
or
this = "Cynthia" and result = 161.8
or
this = "Eunice" and result = 153.2
or
this = "Olive" and result = 179.9
or
this = "Virginia" and result = 165.1
or
this = "Angeline" and result = 172.3
or
this = "Helen" and result = 163.1
or
this = "Cornelia" and result = 160.8
or
this = "Harriet" and result = 163.2
or
this = "Mahala" and result = 157.7
or
this = "Abby" and result = 174.5
or
this = "Margaret" and result = 165.6
or
this = "Deb" and result = 171.6
or
this = "Minerva" and result = 168.7
or
this = "Severus" and result = 188.8
or
this = "Lavina" and result = 155.1
or
this = "Adeline" and result = 165.5
or
this = "Cath" and result = 147.8
or
this = "Elisa" and result = 129.4
or
this = "Lucretia" and result = 153.6
or
this = "Anne" and result = 140.4
or
this = "Eleanor" and result = 151.1
or
this = "Joanna" and result = 167.2
or
this = "Adam" and result = 155.5
or
this = "Agnes" and result = 156.8
or
this = "Rosanna" and result = 162.4
or
this = "Clara" and result = 158.6
or
this = "Melissa" and result = 182.3
or
this = "Amy" and result = 147.1
or
this = "Isabel" and result = 121.4
or
this = "Jemima" and result = 149.8
or
this = "Cordelia" and result = 151.7
or
this = "Melinda" and result = 154.4
or
this = "Delila" and result = 163.4
or
this = "Jeremiah" and result = 167.5
or
this = "Elijah" and result = 184.5
or
this = "Hester" and result = 152.7
or
this = "Walter" and result = 159.6
or
this = "Oliver" and result = 192.4
or
this = "Hugh" and result = 173.1
or
this = "Aaron" and result = 176.6
or
this = "Reuben" and result = 169.9
or
this = "Eli" and result = 180.4
or
this = "Amos" and result = 167.4
or
this = "Augustus" and result = 156.5
or
this = "Theodore" and result = 176.6
or
this = "Ira" and result = 54.1
or
this = "Timothy" and result = 172.2
or
this = "Cyrus" and result = 157.9
or
this = "Horace" and result = 169.3
or
this = "Simon" and result = 157.1
or
this = "Asa" and result = 149.4
or
this = "Frank" and result = 167.2
or
this = "Nelson" and result = 173.0
or
this = "Leonard" and result = 172.0
or
this = "Harrison" and result = 126.0
or
this = "Anthony" and result = 98.4
or
this = "Louis" and result = 186.8
or
this = "Milton" and result = 157.8
or
this = "Noah" and result = 190.5
or
this = "Cornelius" and result = 183.1
or
this = "Abdul" and result = 182.0
or
this = "Warren" and result = 175.0
or
this = "Harvey" and result = 169.3
or
this = "Dennis" and result = 160.4
or
this = "Wesley" and result = 139.8
or
this = "Sylvester" and result = 188.2
or
this = "Gilbert" and result = 177.6
or
this = "Sullivan" and result = 168.3
or
this = "Edmund" and result = 159.2
or
this = "Wilson" and result = 167.6
or
this = "Perry" and result = 189.1
or
this = "Matthew" and result = 167.2
or
this = "Simba" and result = 140.1
or
this = "Nala" and result = 138.0
or
this = "Rafiki" and result = 139.3
or
this = "Shenzi" and result = 171.1
}
/** Gets the location of the person's home ("north", "south", "east", or "west"). If the person is deceased, there is no result. */
string getLocation() {
this = "Ronil" and result = "north"
or
this = "Dina" and result = "north"
or
this = "Ravi" and result = "north"
or
this = "Bruce" and result = "south"
or
this = "Jo" and result = "west"
or
this = "Aida" and result = "east"
or
this = "Esme" and result = "east"
or
this = "Charlie" and result = "south"
or
this = "Fred" and result = "west"
or
this = "Meera" and result = "south"
or
this = "Maya" and result = "south"
or
this = "Chad" and result = "south"
or
this = "Tiana" and result = "west"
or
this = "Laura" and result = "south"
or
this = "George" and result = "south"
or
this = "Will" and result = "south"
or
this = "Mary" and result = "south"
or
this = "Almira" and result = "south"
or
this = "Susannah" and result = "north"
or
this = "Rhoda" and result = "north"
or
this = "Cynthia" and result = "north"
or
this = "Eunice" and result = "north"
or
this = "Olive" and result = "west"
or
this = "Virginia" and result = "west"
or
this = "Angeline" and result = "west"
or
this = "Helen" and result = "west"
or
this = "Cornelia" and result = "east"
or
this = "Harriet" and result = "east"
or
this = "Mahala" and result = "east"
or
this = "Abby" and result = "east"
or
this = "Margaret" and result = "east"
or
this = "Deb" and result = "east"
or
this = "Minerva" and result = "south"
or
this = "Severus" and result = "north"
or
this = "Lavina" and result = "east"
or
this = "Adeline" and result = "west"
or
this = "Cath" and result = "east"
or
this = "Elisa" and result = "east"
or
this = "Lucretia" and result = "north"
or
this = "Anne" and result = "north"
or
this = "Eleanor" and result = "south"
or
this = "Joanna" and result = "south"
or
this = "Adam" and result = "east"
or
this = "Agnes" and result = "east"
or
this = "Rosanna" and result = "east"
or
this = "Clara" and result = "east"
or
this = "Melissa" and result = "west"
or
this = "Amy" and result = "west"
or
this = "Isabel" and result = "west"
or
this = "Jemima" and result = "west"
or
this = "Cordelia" and result = "west"
or
this = "Melinda" and result = "west"
or
this = "Delila" and result = "south"
or
this = "Jeremiah" and result = "north"
or
this = "Elijah" and result = "north"
or
this = "Hester" and result = "east"
or
this = "Walter" and result = "east"
or
this = "Oliver" and result = "east"
or
this = "Hugh" and result = "south"
or
this = "Aaron" and result = "south"
or
this = "Reuben" and result = "west"
or
this = "Eli" and result = "west"
or
this = "Amos" and result = "east"
or
this = "Augustus" and result = "south"
or
this = "Theodore" and result = "west"
or
this = "Ira" and result = "south"
or
this = "Timothy" and result = "north"
or
this = "Cyrus" and result = "north"
or
this = "Horace" and result = "east"
or
this = "Simon" and result = "east"
or
this = "Asa" and result = "east"
or
this = "Frank" and result = "west"
or
this = "Nelson" and result = "west"
or
this = "Leonard" and result = "west"
or
this = "Harrison" and result = "north"
or
this = "Anthony" and result = "north"
or
this = "Louis" and result = "north"
or
this = "Milton" and result = "south"
or
this = "Noah" and result = "south"
or
this = "Cornelius" and result = "east"
or
this = "Abdul" and result = "east"
or
this = "Warren" and result = "west"
or
this = "Harvey" and result = "west"
or
this = "Dennis" and result = "west"
or
this = "Wesley" and result = "west"
or
this = "Sylvester" and result = "south"
or
this = "Gilbert" and result = "east"
or
this = "Sullivan" and result = "east"
or
this = "Edmund" and result = "north"
or
this = "Wilson" and result = "north"
or
this = "Perry" and result = "west"
or
this = "Matthew" and result = "east"
or
this = "Simba" and result = "south"
or
this = "Nala" and result = "south"
or
this = "Rafiki" and result = "north"
or
this = "Shenzi" and result = "west"
}
/** Holds if the person is deceased. */
predicate isDeceased() {
this =
[
"Ernest", "Gertrude", "Oscar", "Lilian", "Edwin", "Raymond", "Elgar", "Elmer", "Herbert",
"Maude", "Mae", "Otto", "Ophelia", "Parsley", "Sage", "Rosemary", "Thyme", "Garfunkel",
"King Basil"
]
}
/** Gets a parent of the person (alive or deceased). */
Person getAParent() {
this = "Stephen" and result = "Edmund"
or
this = "Edmund" and result = "Augustus"
or
this = "Augustus" and result = "Stephen"
or
this = "Abby" and result = "Cornelia"
or
this = "Abby" and result = "Amos"
or
this = "Abdul" and result = "Susannah"
or
this = "Adam" and result = "Amos"
or
this = "Adeline" and result = "Melinda"
or
this = "Adeline" and result = "Frank"
or
this = "Agnes" and result = "Abdul"
or
this = "Aida" and result = "Agnes"
or
this = "Almira" and result = "Sylvester"
or
this = "Amos" and result = "Eunice"
or
this = "Amy" and result = "Noah"
or
this = "Amy" and result = "Chad"
or
this = "Angeline" and result = "Reuben"
or
this = "Angeline" and result = "Lucretia"
or
this = "Anne" and result = "Rhoda"
or
this = "Anne" and result = "Louis"
or
this = "Anthony" and result = "Lavina"
or
this = "Anthony" and result = "Asa"
or
this = "Asa" and result = "Cornelia"
or
this = "Cath" and result = "Harriet"
or
this = "Charlie" and result = "Matthew"
or
this = "Clara" and result = "Ernest"
or
this = "Cornelia" and result = "Cynthia"
or
this = "Cornelius" and result = "Eli"
or
this = "Deb" and result = "Margaret"
or
this = "Dennis" and result = "Fred"
or
this = "Eli" and result = "Susannah"
or
this = "Elijah" and result = "Delila"
or
this = "Elisa" and result = "Deb"
or
this = "Elisa" and result = "Horace"
or
this = "Esme" and result = "Margaret"
or
this = "Frank" and result = "Eleanor"
or
this = "Frank" and result = "Cyrus"
or
this = "George" and result = "Maya"
or
this = "George" and result = "Wilson"
or
this = "Gilbert" and result = "Cornelius"
or
this = "Harriet" and result = "Cynthia"
or
this = "Harrison" and result = "Louis"
or
this = "Harvey" and result = "Fred"
or
this = "Helen" and result = "Susannah"
or
this = "Hester" and result = "Edwin"
or
this = "Hugh" and result = "Cyrus"
or
this = "Hugh" and result = "Helen"
or
this = "Ira" and result = "Maya"
or
this = "Ira" and result = "Wilson"
or
this = "Isabel" and result = "Perry"
or
this = "Isabel" and result = "Harvey"
or
this = "Jemima" and result = "Melinda"
or
this = "Jemima" and result = "Frank"
or
this = "Ernest" and result = "Lilian"
or
this = "Ernest" and result = "Oscar"
or
this = "Gertrude" and result = "Ophelia"
or
this = "Gertrude" and result = "Raymond"
or
this = "Lilian" and result = "Elgar"
or
this = "Lilian" and result = "Mae"
or
this = "Raymond" and result = "Elgar"
or
this = "Raymond" and result = "Mae"
or
this = "Elmer" and result = "Ophelia"
or
this = "Elmer" and result = "Raymond"
or
this = "Herbert" and result = "Ophelia"
or
this = "Herbert" and result = "Raymond"
or
this = "Maude" and result = "Ophelia"
or
this = "Maude" and result = "Raymond"
or
this = "Otto" and result = "Elgar"
or
this = "Otto" and result = "Mae"
or
this = "Edwin" and result = "Otto"
or
this = "Parsley" and result = "Simon"
or
this = "Parsley" and result = "Garfunkel"
or
this = "Sage" and result = "Simon"
or
this = "Sage" and result = "Garfunkel"
or
this = "Rosemary" and result = "Simon"
or
this = "Rosemary" and result = "Garfunkel"
or
this = "Thyme" and result = "Simon"
or
this = "Thyme" and result = "Garfunkel"
or
this = "King Basil" and result = "Ophelia"
or
this = "King Basil" and result = "Raymond"
or
this = "Jo" and result = "Theodore"
or
this = "Joanna" and result = "Shenzi"
or
this = "Laura" and result = "Maya"
or
this = "Laura" and result = "Wilson"
or
this = "Lavina" and result = "Mahala"
or
this = "Lavina" and result = "Walter"
or
this = "Leonard" and result = "Cyrus"
or
this = "Leonard" and result = "Helen"
or
this = "Lucretia" and result = "Eleanor"
or
this = "Lucretia" and result = "Cyrus"
or
this = "Mahala" and result = "Eunice"
or
this = "Margaret" and result = "Cynthia"
or
this = "Matthew" and result = "Cyrus"
or
this = "Matthew" and result = "Helen"
or
this = "Maya" and result = "Meera"
or
this = "Melinda" and result = "Rafiki"
or
this = "Melissa" and result = "Mahala"
or
this = "Melissa" and result = "Walter"
or
this = "Nala" and result = "Bruce"
or
this = "Nelson" and result = "Mahala"
or
this = "Nelson" and result = "Walter"
or
this = "Noah" and result = "Eli"
or
this = "Olive" and result = "Reuben"
or
this = "Olive" and result = "Lucretia"
or
this = "Oliver" and result = "Matthew"
or
this = "Perry" and result = "Leonard"
or
this = "Ravi" and result = "Dina"
or
this = "Simba" and result = "Will"
or
this = "Simon" and result = "Margaret"
or
this = "Sullivan" and result = "Cornelius"
or
this = "Sylvester" and result = "Timothy"
or
this = "Theodore" and result = "Susannah"
or
this = "Tiana" and result = "Jo"
or
this = "Virginia" and result = "Helen"
or
this = "Warren" and result = "Shenzi"
or
this = "Wesley" and result = "Warren"
or
this = "Wesley" and result = "Jo"
or
this = "Will" and result = "Eli"
}
/** Holds if the person is allowed in the region. Initially, all villagers are allowed in every region. */
predicate isAllowedIn(string region) { region = ["north", "south", "east", "west"] }
}
/** Returns a parent of the person. */
Person parentOf(Person p) { result = p.getAParent() }