docs for hashed index keys, merged restrictions and narrower where modesindexes

1 files changed, 6 insertions, 5 deletions

diff --git a/docs/modes.org b/docs/modes.org
index 1cd5905..2da300a 100644
--- a/docs/modes.org
+++ b/docs/modes.org
@@ -135,10 +135,11 @@ executes anything, and records them on each relation it derives.
 - =Base r= has the modes of =r=.
 - =Project (p, A)= keeps the modes of =p= whose =bound= lies within
   =A=, with the same =yields=.
-- =Where (Base r, b)=, when =r= offers an index on an attribute =b=
-  binds, has the modes of =r= with the attributes of =b= taken out of
-  each =bound=, by =Mode.given=. The binding supplies their values, and
-  the index produces the tuples, so ={a; Finite}= becomes ={∅; Finite}=.
+- =Where (Base r, b)=, when =r= offers an index on an attribute =a= that
+  =b= binds, has the modes of =r= with =a= taken out of each =bound=, by
+  =Mode.given=. The binding supplies its value, and the index produces
+  the tuples, so ={a; Finite}= becomes ={∅; Finite}=. The other attributes
+  of =b= only filter what the index produces, so they stay bound.
 - Any other =Where (p, b)= keeps the modes of =p=, since it can only
   filter what =p= enumerates.
 
@@ -171,7 +172,7 @@ with =undecidable-membership=.
 
 * Indexes
 A substantial relation keeps an index on each attribute =a=, a tree
-keyed by the encoded value of =a= and the hash of the tuple, and each
+keyed by the hash of the value of =a= and the hash of the tuple, and each
 adds the mode ={a; Finite}=. A projection that keeps =a= keeps that mode,
 and a FOL =Where= that binds =a= reads only the matching entries.
 [[file:partial-bindings.org][Partial bindings]] describes how the indexes are stored, read and built.