# HG changeset patch
# User wenzelm
# Date 949766067 -3600
# Node ID af2575a5c5aef99ddd46437ee9b0ec0dc06ef8a7
# Parent  0c5d9d23b7152e53aa615c7282d13de3d9ae0a27
'.' == by this;

diff -r 0c5d9d23b715 -r af2575a5c5ae doc-src/IsarRef/generic.tex
--- a/doc-src/IsarRef/generic.tex	Fri Feb 04 21:53:36 2000 +0100
+++ b/doc-src/IsarRef/generic.tex	Sat Feb 05 16:54:27 2000 +0100
@@ -3,12 +3,14 @@
 
 \section{Basic proof methods}\label{sec:pure-meth}
 
-\indexisarmeth{fail}\indexisarmeth{succeed}\indexisarmeth{$-$}\indexisarmeth{assumption}
+\indexisarmeth{fail}\indexisarmeth{succeed}\indexisarmeth{$-$}
+\indexisarmeth{assumption}\indexisarmeth{this}
 \indexisarmeth{fold}\indexisarmeth{unfold}
 \indexisarmeth{rule}\indexisarmeth{erule}
 \begin{matharray}{rcl}
   - & : & \isarmeth \\
   assumption & : & \isarmeth \\
+  this & : & \isarmeth \\
   rule & : & \isarmeth \\
   erule^* & : & \isarmeth \\[0.5ex]
   fold & : & \isarmeth \\
@@ -29,8 +31,9 @@
   plain \emph{do-nothing} proof step would be $\PROOF{-}$ rather than
   $\PROOFNAME$ alone.
 \item [$assumption$] solves some goal by assumption.  Any facts given are
-  guaranteed to participate in the refinement.  Note that ``$\DOT$'' (dot)
-  abbreviates $\BY{assumption}$.
+  guaranteed to participate in the refinement.
+\item [$this$] applies the current facts directly as rules.  Note that
+  ``$\DOT$'' (dot) abbreviates $\BY{this}$.
 \item [$rule~thms$] applies some rule given as argument in backward manner;
   facts are used to reduce the rule before applying it to the goal.  Thus
   $rule$ without facts is plain \emph{introduction}, while with facts it
diff -r 0c5d9d23b715 -r af2575a5c5ae doc-src/IsarRef/pure.tex
--- a/doc-src/IsarRef/pure.tex	Fri Feb 04 21:53:36 2000 +0100
+++ b/doc-src/IsarRef/pure.tex	Sat Feb 05 16:54:27 2000 +0100
@@ -718,7 +718,7 @@
 \item [``$\DDOT$''] is a \emph{default proof}\index{proof!default}; it
   abbreviates $\BY{default}$.
 \item [``$\DOT$''] is a \emph{trivial proof}\index{proof!trivial}; it
-  abbreviates $\BY{assumption}$.
+  abbreviates $\BY{this}$.
 \item [$\isarkeyword{sorry}$] is a \emph{fake proof}\index{proof!fake};
   provided that the \texttt{quick_and_dirty} flag is enabled,
   $\isarkeyword{sorry}$ pretends to solve the goal without further ado.  Of
diff -r 0c5d9d23b715 -r af2575a5c5ae doc-src/IsarRef/refcard.tex
--- a/doc-src/IsarRef/refcard.tex	Fri Feb 04 21:53:36 2000 +0100
+++ b/doc-src/IsarRef/refcard.tex	Sat Feb 05 16:54:27 2000 +0100
@@ -41,7 +41,7 @@
 \begin{matharray}{rcl}
   \BYY{m@1}{m@2} & \equiv & \PROOF{m@1}~\QED{m@2} \\
   \DDOT & \equiv & \BY{rule} \\
-  \DOT & \equiv & \BY{assumption} \\
+  \DOT & \equiv & \BY{this} \\
   \HENCENAME & \equiv & \THEN~\HAVENAME \\
   \THUSNAME & \equiv & \THEN~\SHOWNAME \\
   \FROM{a@1\;\dots\;a@n} & \equiv & \NOTE{this}{a@1\;\dots\;a@n}~\THEN \\
@@ -79,6 +79,7 @@
 \begin{tabular}{ll}
   \multicolumn{2}{l}{\textbf{Single steps (forward-chaining facts)}} \\[0.5ex]
   $assumption$ & apply some assumption \\
+  $this$ & apply current facts \\
   $rule~a@1\;\dots\;a@n$ & apply some rule  \\
   $rule$ & apply standard rule (default for $\PROOFNAME$) \\
   $induct~x$ & apply induction rule \\
diff -r 0c5d9d23b715 -r af2575a5c5ae src/Pure/Isar/method.ML
--- a/src/Pure/Isar/method.ML	Fri Feb 04 21:53:36 2000 +0100
+++ b/src/Pure/Isar/method.ML	Sat Feb 05 16:54:27 2000 +0100
@@ -41,6 +41,7 @@
   val erule_tac: thm list -> thm list -> int -> tactic
   val rule: thm list -> Proof.method
   val erule: thm list -> Proof.method
+  val this: Proof.method
   val assumption: Proof.context -> Proof.method
   exception METHOD_FAIL of (string * Position.T) * exn
   val help_methods: theory option -> unit
@@ -281,7 +282,12 @@
 end;
 
 
-(* assumption / finish *)
+(* this *)
+
+val this = METHOD (EVERY o map (FINDGOAL o Tactic.rtac));
+
+
+(* assumption *)
 
 fun assm_tac ctxt =
   assume_tac APPEND' resolve_tac (filter Thm.no_prems (ProofContext.prems_of ctxt));
@@ -291,7 +297,6 @@
   | assumption_tac _ _ = K no_tac;
 
 fun assumption ctxt = METHOD (FINDGOAL o assumption_tac ctxt);
-fun finish ctxt = METHOD (K (FILTER Thm.no_prems (ALLGOALS (assm_tac ctxt) THEN flexflex_tac)));
 
 
 
@@ -458,6 +463,9 @@
 (* structured proof steps *)
 
 val default_text = Source (Args.src (("default", []), Position.none));
+val this_text = Basic (K this);
+
+fun finish ctxt = METHOD (K (FILTER Thm.no_prems (ALLGOALS (assm_tac ctxt) THEN flexflex_tac)));
 
 fun finish_text None = Basic finish
   | finish_text (Some txt) = Then [txt, Basic finish];
@@ -470,7 +478,7 @@
 
 fun local_qed opt_text = Proof.local_qed (refine (finish_text opt_text));
 fun local_terminal_proof (text, opt_text) pr = Seq.THEN (proof (Some text), local_qed opt_text pr);
-val local_immediate_proof = local_terminal_proof (Basic assumption, None);
+val local_immediate_proof = local_terminal_proof (this_text, None);
 val local_default_proof = local_terminal_proof (default_text, None);
 
 
@@ -490,7 +498,7 @@
   |> Proof.check_result "Failed to finish proof (after successful terminal method)" state
   |> Seq.hd;
 
-val global_immediate_proof = global_terminal_proof (Basic assumption, None);
+val global_immediate_proof = global_terminal_proof (this_text, None);
 val global_default_proof = global_terminal_proof (default_text, None);
 
 
@@ -509,6 +517,7 @@
   ("default", thms_ctxt_args some_rule, "apply some rule"),
   ("rule", thms_ctxt_args some_rule, "apply some rule"),
   ("erule", thms_ctxt_args some_erule, "apply some erule (improper!)"),
+  ("this", no_args this, "apply current facts as rules"),
   ("assumption", ctxt_args assumption, "proof by assumption, preferring facts")];