<table name="basic_2_sum"/>
<subsection name="B">Stage "B"</subsection>
+ <news class="beta" date="2019 March 25.">
+ Preservation of validity for rt-computation
+ does not need the sort degree parameter
+ (i.e. no induction on the degree).
+ </news>
<news class="beta" date="2018 November 1.">
Extended (λδ-2) and restricted (λδ-1) type rules justified.
</news>