1 | 1. hyp: Formula List 2. concl: Formula List 3. S:Sequent.
(S) < ( < hyp,concl > ) 
( L:Sequent List. s L.( (s) = 0) & ( s L.|= s  |= S ) & ( a:Assignment. s L.a | s  a | S)) L:Sequent List.
s L.( (s) = 0) & ( s L.|= s  |= < hyp,concl > ) & ( a:Assignment. s L.a | s  a | < hyp,concl > ) |