[Programming side] variable [Logic side] 
axiom
a x i o m
i n t r o d u c t i o n r u l e
e l i m i n a t i o n r u l e
n o r m a l d e d u c t i o n
n o r m a l i s a t i o n o f d e d u c t i o n s
p r o v a b i l i t y
i n t u i t i o n i s t i c t a u t o l o g y