Definition of equipollency in US English:

equipollency

noun

archaic
  • See equipollent

    • ‘In 1835 and 1837 he published two papers on equipollencies which many consider to be his most important contributions to mathematics.’
    • ‘The principle of dynamic equipollency makes possible an efficient method of dealing with a structure having many degrees of freedom.’
    • ‘Now the cause of these equipollencies is that in the assertions mentioned above we may consider quantity, i.e. universality and particularity, and quality, i.e. negation and affirmation.’