DOC: Add CUSTOM_ID properties to README.org headings where needed

diff --git a/README.org b/README.org
index e6450c0d8ebdeb1b6bb8df5a56bf76421110fce3..c5dfa3f0bbebcda12e6263d574cfbda4d48702ac 100644 (file)
--- a/README.org
+++ b/README.org
@@ -83,6 +83,9 @@ The different parts of =sweep= are structured as follows:
    SWI-Prolog runtime may need to be built as well.
 
 * TODO Prolog initialization and cleanup
+:PROPERTIES:
+:CUSTOM_ID: prolog-init
+:END:
 
 #+VINDEX: sweep-init-on-load
 #+VINDEX: sweep-init-args
@@ -138,6 +141,9 @@ close the current query, but =sweep-close-query= also destroys any
 Prolog bindings created by the query.
 
 ** Conversion of Elisp objects to Prolog terms
+:PROPERTIES:
+:CUSTOM_ID: elisp-to-prolog
+:END:
 
 =sweep= converts Elisp objects into Prolog terms to allow the Elisp
 programmers to specify arguments for Prolog predicates invocations (see
@@ -154,6 +160,9 @@ we convert /trees of strings and numbers/:
   are the Prolog representations of the =car= and the =cdr= of the cons.
 
 ** Conversion of Prolog terms to Elisp objects
+:PROPERTIES:
+:CUSTOM_ID: prolog-to-elisp
+:END:
 
 =sweep= converts Prolog terms into Elisp object to allow efficient
 processing of Prolog query results in Elisp (see =sweep-next-solution=).
@@ -176,6 +185,9 @@ processing of Prolog query results in Elisp (see =sweep-next-solution=).
   + Prolog dicts are converted to the symbol =dict=.
 
 ** Example - counting solutions for a Prolog predicate in Elisp
+:PROPERTIES:
+:CUSTOM_ID: count-permutations
+:END:
 
 As an example of using the =sweep= interface for executing Prolog
 queries, we show an invocation of the non-deterministic predicate
@@ -196,6 +208,9 @@ permutations of the list =(1 2 3 4 5)=:
 
 
 * The Prolog top-level
+:PROPERTIES:
+:CUSTOM_ID: prolog-top-level
+:END:
 
 #+FINDEX: sweep-top-level
 =sweep= provides a classic Prolog top-level interface for interacting
@@ -227,6 +242,9 @@ command =M-x sweep-find-predicate= jumping to the definition a
 loaded or auto-loadable Prolog predicate.
 
 * Installing Prolog packages
+:PROPERTIES:
+:CUSTOM_ID: prolog-packages
+:END:
 
 #+FINDEX: sweep-pack-install
 The command =M-x sweep-pack-install= can be used to install