diff --git a/Ledger/Amount.hs b/Ledger/Amount.hs
index ea42bee6a..29023b5c2 100644
--- a/Ledger/Amount.hs
+++ b/Ledger/Amount.hs
@@ -10,30 +10,27 @@ A simple amount is a 'Commodity', quantity pair:
   EUR 3.44 
   GOOG 500
   1.5h
-  90apples
+  90 apples
   0 
 @
 
-A 'MixedAmount' is zero or more simple amounts:
-
-@
-  $50 + EUR 3
-  16h + $13.55 + AAPL 500 + 6 oranges
-@
-
-Amounts often have a price per unit, or conversion rate, in terms of
-another commodity. If present, this is displayed after \@:
+An amount may also have a per-unit price, or conversion rate, in terms
+of some other commodity. If present, this is displayed after \@:
 
 @
   EUR 3 \@ $1.35
 @
 
-A normalised mixed amount has at most one amount in each commodity-price,
-and no zero amounts (or it has just a single zero amount and no others.)
+A 'MixedAmount' is zero or more simple amounts.  Mixed amounts are
+usually normalised so that there is no more than one amount in each
+commodity, and no zero amounts (or, there is just a single zero amount
+and no others.):
 
-In principle we can convert an amount to any other commodity to which we
-have a known sequence of conversion rates; in practice we only do one
-conversion step (eg to show cost basis with -B).
+@
+  $50 + EUR 3
+  16h + $13.55 + AAPL 500 + 6 oranges
+  0
+@
 
 We can do limited arithmetic with simple or mixed amounts: either
 price-preserving arithmetic with similarly-priced amounts, or