docs: update to define integer overflow

Change-Id: Ie8a1b31035f2d27a220e5df2e9e178ec3b39ee68

2 files changed, 7 insertions, 2 deletions

diff --git a/doc/manual/src/language/operators.md b/doc/manual/src/language/operators.md
index 418d0349f..ff09e739f 100644
--- a/doc/manual/src/language/operators.md
+++ b/doc/manual/src/language/operators.md
@@ -59,8 +59,10 @@ The result is a [Boolean] value.
 
 ## Arithmetic
 
-Numbers are type-compatible:
-Pure integer operations will always return integers, whereas any operation involving at least one floating point number return a floating point number.
+Numbers will retain their type unless mixed with other numeric types:
+Pure integer operations will always return integers, whereas any operation involving at least one floating point number returns a floating point number.
+
+Integer overflow (of 64-bit signed integers) and division by zero are defined to throw an error.
 
 See also [Comparison] and [Equality].
 
diff --git a/doc/manual/src/language/values.md b/doc/manual/src/language/values.md
index 2ae3e143a..f02ef2597 100644
--- a/doc/manual/src/language/values.md
+++ b/doc/manual/src/language/values.md
@@ -85,6 +85,9 @@
   Numbers, which can be *integers* (like `123`) or *floating point*
   (like `123.43` or `.27e13`).
 
+  Integers in the Nix language are 64-bit signed integers.
+  Integer overflow is defined to throw an error.
+
   See [arithmetic] and [comparison] operators for semantics.
 
   [arithmetic]: ./operators.md#arithmetic