+++ /dev/null
-(**************************************************************************)
-(* ___ *)
-(* ||M|| *)
-(* ||A|| A project by Andrea Asperti *)
-(* ||T|| *)
-(* ||I|| Developers: *)
-(* ||T|| The HELM team. *)
-(* ||A|| http://helm.cs.unibo.it *)
-(* \ / *)
-(* \ / This file is distributed under the terms of the *)
-(* v GNU General Public License Version 2 *)
-(* *)
-(**************************************************************************)
-
-include "delayed_updating/substitution/fsubst.ma".
-include "delayed_updating/substitution/lift_prototerm.ma".
-include "delayed_updating/syntax/prototerm_eq.ma".
-include "delayed_updating/syntax/path_closed.ma".
-include "delayed_updating/notation/relations/black_rightarrow_if_3.ma".
-include "ground/relocation/tr_uni.ma".
-include "ground/xoa/ex_4_3.ma".
-
-(* IMMEDIATE FOCUSED REDUCTION ************************************************)
-
-definition ifr (r): relation2 prototerm prototerm ≝
- λt1,t2.
- ∃∃p,q,n. p●𝗔◗𝗟◗q = r &
- q ϵ 𝐂❨Ⓕ,n❩ & r◖𝗱↑n ϵ t1 &
- t1[⋔r←🠡[𝐮❨↑n❩](t1⋔(p◖𝗦))] ⇔ t2
-.
-
-interpretation
- "focused reduction with immediate updating (prototerm)"
- 'BlackRightArrowIF t1 r t2 = (ifr r t1 t2).