/* database program which compute coutnries with the same population density */ population china := 8250. population india := 5863. population ussr := 2521. population usa := 2119. population indonesia := 1276. population japan := 1097. population brazil := 1042. population bangladesh := 750. population pakistan := 682. population germany := 620. population nigeria := 613. population mexico := 581. population uk := 559. population italy := 554. population france := 525. population philippines := 415. population thailand := 410. population turkey := 383. population egypt := 364. population spain := 352. population poland := 337. population korea := 335. population iran := 320. population ethiopia := 272. population argentina := 251. area china := 3380. area india := 1139. area ussr := 8708. area usa := 3609. area indonesia := 570. area japan := 148. area brazil := 3288. area bangladesh := 55. area pakistan := 311. area germany := 96. area nigeria := 373. area mexico := 764. area uk := 86. area italy := 116. area france := 213. area philippines := 90. area thailand := 200. area turkey := 296. area egypt := 386. area spain := 190. area poland := 121. area korea := 37. area iran := 628. area ethiopia := 350. area argentina := 1080. density Country := div (mult 100 (population Country)) (area Country). samedensity( C1, D1, C2, D2) :- D1 = (density C1), D2 = (density C2), D1 > D2, (20*D1) < (21*D2). /*samedensity1( C1, C2) := letpar D1 = (density C1), D2 = (density C2) in if (D1 > D2, (20*D1) < (21*D2)) then true. */ /* goal: samedensity(C1,D1,C2,D4) */