?? ... non-invertible morphisms between (underlying modules of) fractional ideals .... ??? vs ... ???? non-invertible morphisms between elliptic curves (?? with complex multiplication ... ??? ...) ... ???? ??very unclear ??? ....

???hall algebra (???for elliptic curves ??? ....) vs hecke operator ... ??? .....

???kernel of non-invertible morphism between elliptic curves (?? for example with complex multiplication ...) ... ??? as "equal-division points" .... ??? ....

??? "fomral group law" for elliptic curve ... differential equation ... "tradeoff between space-independence and time-independence" ... ??? ...

?? "theta function" ...

?? peirce quincunxial projection ... ???....