Small updates to the text and typos

Author: mcol

src/reference-manual/blocks.Rmd

@@ -82,8 +82,9 @@ block.  Most functions can be used in any block and applied to a
 mixture of parameters and data (including constants or program
 literals).
 
-Random-number-generating functions are restricted to the generated
-quantities block; such functions are suffixed with `_rng`.
+Random-number-generating functions are restricted to transformed data
+and generated quantities blocks, and within user-defined functions
+ending in `_rng`; such functions are suffixed with `_rng`.
 Log-probability modifying functions to blocks where the log
 probability accumulator is in scope (transformed parameters and
 model); such functions are suffixed with `_lp`.

src/reference-manual/user-functions.Rmd

@@ -20,8 +20,8 @@ data {
 
 Function definitions and declarations may appear in any order, subject
 to the condition that a function must be declared before it is used.
-Forward declarations are allowed in order to support recursive
-functions.
+[Forward declarations](#forward-declarations.section) are allowed in
+order to support recursive functions.
 
 
 ## Function Names
@@ -182,7 +182,7 @@ number generators are available;  see the rest of this section for details.
 
 Functions that call random number generating functions in their bodies
 must have a name that ends in `_rng`; attempts to use
-random-number generators in other functions leads to a compile-time
+random-number generators in other functions lead to a compile-time
 error.
 
 Like other random number generating functions, user-defined functions
@@ -197,7 +197,7 @@ a function elsewhere results in a compile-time error.
 Functions that include sampling statements or log probability
 increment statements must have a name that ends in `_lp`.
 Attempts to use sampling statements or increment log probability
-statements in other functions leads to a compile-time error.
+statements in other functions lead to a compile-time error.
 
 Like the target log density increment statement and sampling
 statements, user-defined functions with names that end in `_lp`
@@ -251,7 +251,7 @@ the log of the density or mass function it defines.
 Within function definition bodies, the parameters may be used like any
 other variable.  But the parameters are constant in the sense that
 they can't be assigned to (i.e., can't appear on the left side of an
-assignment (`=`) statement)<.  In other words, their value remains
+assignment (`=`) statement).  In other words, their value remains
 constant throughout the function body.  Attempting to assign a value
 to a function parameter value will raise a compile-time error.^[Despite being declared constant and appearing to have a pass-by-value syntax in Stan, the implementation of the language passes function arguments by constant reference in C++.]
 
@@ -367,7 +367,7 @@ without bodies.  For example,
 real unit_normal_lpdf(real y);
 ```
 
-declares a function named `unit_normal_log` that consumes a
+declares a function named `unit_normal_lpdf` that consumes a
 single real-valued input and produces a real-valued output.  A
 function definition with a body simultaneously declares and defines
 the named function, as in