val fold :
init:'acc__0->row_var:('acc__0->(row_var->bcast)Variantslib.Variant.t->'acc__1)->broadcastable:('acc__1->bcastVariantslib.Variant.t->'acc__2)->'acc__2
val iter :
row_var:((row_var->bcast)Variantslib.Variant.t->Base.unit)->broadcastable:(bcastVariantslib.Variant.t->Base.unit)->Base.unit
val map :
bcast->row_var:((row_var->bcast)Variantslib.Variant.t->row_var->'result__)->broadcastable:(bcastVariantslib.Variant.t->'result__)->'result__