Apply suggestions from code review

Author: skirpichev

Doc/c-api/float.rst

@@ -157,7 +157,7 @@ Floating-Point Objects
 
 .. c:macro:: Py_IS_FINITE(X)
 
-   Determines if the given floating-point number has finite value,
+   Determines if the given floating-point number *X* has finite value,
    that is, it is normal, subnormal or zero, but not infinite or NaN.
 
    .. deprecated:: 3.14
@@ -166,7 +166,7 @@ Floating-Point Objects
 
 .. c:macro:: Py_IS_INFINITY(X)
 
-   Determines if the given floating-point number is positive or negative
+   Determines if the given floating-point number *X* is positive or negative
    infinity.
 
    .. deprecated:: 3.14
@@ -175,7 +175,7 @@ Floating-Point Objects
 
 .. c:macro:: Py_IS_NAN(X)
 
-   Determines if the given floating-point number is a not-a-number (NaN) value.
+   Determines if the given floating-point number *X* is a not-a-number (NaN) value.
 
    .. deprecated:: 3.14
       The macro is :term:`soft deprecated`.  Use :c:macro:`!isnan` instead.