typo, clarifications

frustration.4th

@@ -31,7 +31,7 @@ Let's explain how it works.
 
 LINE 1    : rdup   r>  r> dup >r >r  >r ;
 LINE 2    : rdrop  r>  r> drop  >r ;
-LINE 3    : loop[  [ ' setup lit ] , [ ' rdrop lit ] , ; immediate
+LINE 3    : loop[  [ ' rdup lit ] , [ ' rdrop lit ] , ; immediate
 LINE 4    : ]loop  latest @ 8 + , ; immediate
 
 Line 1-4 are defining a new loop construct called loop[ ... ]loop that

frustration.rs

@@ -645,8 +645,8 @@ const PRIMITIVES: [Primitive; 16] = [
 /* You now have an unfamiliar computer with no software.  Can you and the
  * computer write a program?
  *
- * The first program is the hardest to write because you don't have any tools to
- * help write it.  The computer itself is going to be no help.  Without any
+ * The first program is the hardest to write because you don't have any tools
+ * to help write it.  The computer itself is going to be no help.  Without any
  * program it will sit there doing nothing.
  *
  * What should the first program be?
@@ -2206,10 +2206,10 @@ fn main() {
 /* Now we can start programming in "real" Forth, not a weird macro language
  * inside Rust.
  *
- * You can compile this Forth with:
+ * You can compile our Forth computer with:
  *     rustc frustration.rs
  *
- * You can run this Forth with:
+ * You can run our Forth computer with:
  *     ./frustration
  *
  * However, I recommend loading a Forth program (frustration.4th, provided)
@@ -2225,6 +2225,6 @@ fn main() {
  *
  *     bash build.sh
  * 
- * Please read frustration.4th if you want to learn more about Forth and what
- * makes it a unique language.
+ * Please read frustration.4th if you want to learn more about how to
+ * use Forth.
  */