principal unit normalprincipal unknownsprincipal valueprincipal value of an integralprincipal value of argumentprincipal value of integralprincipal value of logarithmprincipal value of logzprincipiaprincipleprinciple of choiceprinciple of completenessprinciple of conditionalityprinciple of conservation of energyprinciple of countingprinciple of deformationprinciple of detailed balanceprinciple of diminishing returnsprinciple of dualityprinciple of duality in a spherical triangleprinciple of economyprinciple of equivalenceprinciple of extensionprinciple of first differenceprinciple of generalizationprinciple of inclusion and exclusionprinciple of inductionprinciple of insufficient reasonprinciple of least actionprinciple of likelihoodprinciple of mathematical inductionprinciple of nested intervalsprinciple of non contradictionprinciple of optimalityprinciple of smallest integerprinciple of specificationprinciple of sufficiencyprinciple of superpositionprinciple of the first differenceprinciple of the maximumprinciple of the minimumprinit outprintprinted circuitpriorprior deductionprior distributionprior informationprior probabilityprior probability of parameters