>I remember Norm wrote a message to the mailing list (which I'm not sure how to find) about why we use e. and C_ for ordinal less than and ordinal no greater than, rather than having, say, <o and <_o (I think he even said we tried the latter for a while).
I think you mean the following post of Norm about philosophy and goals of set.mm: https://groups.google.com/g/metamath/c/mnkBQV1_cXc/m/zz4C8_2KAAAJ The paragraph "rules for introducing new definitions" is especially relevant. -- You received this message because you are subscribed to the Google Groups "Metamath" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/metamath/13af2ad6-951d-4d34-918a-9ab46d4fb01an%40googlegroups.com.
