fix typos

Author: mark-i-m

src/appendix/glossary.md

@@ -65,7 +65,7 @@ soundness               |  soundness is a technical term in type theory. Roughly
 span                    |  a location in the user's source code, used for error reporting primarily. These are like a file-name/line-number/column tuple on steroids: they carry a start/end point, and also track macro expansions and compiler desugaring. All while being packed into a few bytes (really, it's an index into a table). See the Span datatype for more.
 substs                  |  the substitutions for a given generic type or item (e.g. the `i32`, `u32` in `HashMap<i32, u32>`)
 tcx                     |  the "typing context", main data structure of the compiler ([see more](../ty.html))
-'tcx                    |  the lifetime of the currently active inference context ([see more](../ty.html))
+'tcx                    |  the lifetime of the allocation arena ([see more](../ty.html))
 trait reference         |  the name of a trait along with a suitable set of input type/lifetimes ([see more](../traits/goals-and-clauses.html#trait-ref))
 token                   |  the smallest unit of parsing. Tokens are produced after lexing ([see more](../the-parser.html)).
 [TLS]                   |  Thread-Local Storage. Variables may be defined so that each thread has its own copy (rather than all threads sharing the variable). This has some interactions with LLVM. Not all platforms support TLS.

src/conventions.md

@@ -141,7 +141,7 @@ to the compiler.
 - `cx` tends to be short for "context" and is often used as a suffix. For
   example, `tcx` is a common name for the [Typing Context][tcx].
 
-- [`'tcx`][tcx] is used as the lifetim names for the Typing Context.
+- [`'tcx`][tcx] is used as the lifetime name for the Typing Context.
 
 - Because `crate` is a keyword, if you need a variable to represent something
   crate-related, often the spelling is changed to `krate`.