1. A

    Another Opus Here

    This thread deals with ordinal numbers: Ordinal Number -- from Wolfram MathWorld The standard less-than ordinal comparison, $<$, implies that $\alpha < \beta$ if and only if $\alpha$ is order isomorphic to an initial segment of $\beta$. The class of ordinal numbers are well ordered by the...
  2. A

    My Opus

    I assume there may be something wrong and this isn't actually my opus because the result of this work is to show that two sets of equal cardinality do not have equal cardinality (a contradiction) using only standard theory that can be adapted to a model of ZF. ZF would therefore be...