injection_tac and discriminate_tac now replaced by destruct_tac that

[helm.git] / matita / help / C / sec_tactics.xml

diff --git a/matita/help/C/sec_tactics.xml b/matita/help/C/sec_tactics.xml
index cd26700ab703a885027108ae4bd5fa217dea8830..468a27695c6e64495fd5450cc66b0eed395de912 100644 (file)
--- a/matita/help/C/sec_tactics.xml
+++ b/matita/help/C/sec_tactics.xml
@@ -536,30 +536,35 @@
       </variablelist>
     </para>
   </sect1>
-  <sect1 id="tac_discriminate">
-    <title>discriminate</title>
-    <titleabbrev>discriminate</titleabbrev>
-    <para><userinput>discriminate p</userinput></para>
+  <sect1 id="tac_destruct">
+    <title>destruct</title>
+    <titleabbrev>destruct</titleabbrev>
+    <para><userinput>destruct p</userinput></para>
     <para>
       <variablelist>
         <varlistentry role="tactic.synopsis">
           <term>Synopsis:</term>
           <listitem>
-            <para><emphasis role="bold">discriminate</emphasis> &sterm;</para>
+            <para><emphasis role="bold">destruct</emphasis> &sterm;</para>
           </listitem>
         </varlistentry>
         <varlistentry>
           <term>Pre-conditions:</term>
           <listitem>
-            <para><command>p</command> must have type <command>K t<subscript>1</subscript> ... t<subscript>n</subscript> = K' t'<subscript>1</subscript> ... t'<subscript>m</subscript></command> where <command>K</command> and <command>K'</command> must be different constructors of the same inductive type and each argument list can be empty if
-its constructor takes no arguments.</para>
+            <para><command>p</command> must have type <command>E<subscript>1</subscript> = E<subscript>2</subscript></command> where the two sides of the equality are possibly applied constructors of an inductive type.</para>
           </listitem>
         </varlistentry>
         <varlistentry>
           <term>Action:</term>
           <listitem>
-            <para>It closes the current sequent by proving the absurdity of
-             <command>p</command>.</para>
+            <para>The tactic recursively compare the two sides of the equality
+             looking for different constructors in corresponding position.
+             If two of them are found, the tactic closes the current sequent
+             by proving the absurdity of <command>p</command>. Otherwise
+             it adds a new hypothesis for each leaf of the formula that
+             states the equality of the subformulae in the corresponding
+             positions on the two sides of the equality.
+            </para>
           </listitem>
         </varlistentry>
         <varlistentry>
@@ -950,43 +955,6 @@ its constructor takes no arguments.</para>
       </variablelist>
     </para>
   </sect1>
-  <sect1 id="tac_injection">
-    <title>injection</title>
-    <titleabbrev>injection</titleabbrev>
-    <para><userinput>injection p</userinput></para>
-    <para>
-      <variablelist>
-        <varlistentry role="tactic.synopsis">
-          <term>Synopsis:</term>
-          <listitem>
-            <para><emphasis role="bold">injection</emphasis> &sterm;</para>
-          </listitem>
-        </varlistentry>
-        <varlistentry>
-          <term>Pre-conditions:</term>
-          <listitem>
-            <para><command>p</command> must have type <command>K t<subscript>1</subscript> ... t<subscript>n</subscript> = K t'<subscript>1</subscript> ... t'<subscript>n</subscript></command> where both argument lists are empty if
-<command>K</command> takes no arguments.</para>
-          </listitem>
-        </varlistentry>
-        <varlistentry>
-          <term>Action:</term>
-          <listitem>
-            <para>It derives new hypotheses by injectivity of
-             <command>K</command>.</para>
-          </listitem>
-        </varlistentry>
-        <varlistentry>
-          <term>New sequents to prove:</term>
-          <listitem>
-            <para>The new sequent to prove is equal to the current sequent
-             with the additional hypotheses
-             <command>t<subscript>1</subscript>=t'<subscript>1</subscript></command> ... <command>t<subscript>n</subscript>=t'<subscript>n</subscript></command>.</para>
-          </listitem>
-        </varlistentry>
-      </variablelist>
-    </para>
-  </sect1>
   <sect1 id="tac_intro">
     <title>intro</title>
     <titleabbrev>intro</titleabbrev>