(* NOTATION FOR THE FORMAL SYSTEM λδ ****************************************)
-notation "hvbox( L1 ≡ [ break term 46 f ] break term 46 L2 )"
+notation "hvbox( L1 ≡[ break term 46 f ] break term 46 L2 )"
non associative with precedence 45
for @{ 'IdEqSn $f $L1 $L2 }.