--- gforth/float.fs	1999/05/06 21:33:32	1.26
+++ gforth/float.fs	1999/12/03 18:24:22	1.29
@@ -66,29 +66,29 @@ dofield: lastxt code-address! \ change t
     \G @i{f} in the space.
     here 1 floats allot f! ;
 
-: fconstant  ( r "name" -- ) \ float
+: fconstant  ( r "name" -- ) \ float f-constant
     Create f,
 DOES> ( -- r )
     f@ ;
 
-: fdepth ( -- +n ) \ floating f-depth
-    \G @var{+n} is the current number of (floating-point) values on the
+: fdepth ( -- +n ) \ float f-depth
+    \G @i{+n} is the current number of (floating-point) values on the
     \G floating-point stack.
     fp0 @ fp@ - [ 1 floats ] Literal / ;
 
 : FLit ( -- r )  r> dup f@ float+ >r ;
-: FLiteral ( compilation r -- ; run-time -- r ) \ float
-    \G Compile appropriate code such that, at run-time, @var{r} is placed
+: FLiteral ( compilation r -- ; run-time -- r ) \ float f-literal
+    \G Compile appropriate code such that, at run-time, @i{r} is placed
     \G on the (floating-point) stack. Interpretation semantics are undefined.
     BEGIN  here cell+ dup faligned <>  WHILE  postpone noop  REPEAT
     postpone FLit  f, ;  immediate
 
-&15 Value precision ( -- u ) \ floating-ext
-\G @var{u} is the number of significant digits currently used by
+&15 Value precision ( -- u ) \ float-ext
+\G @i{u} is the number of significant digits currently used by
 \G @code{F.} @code{FE.} and @code{FS.} 
-: set-precision ( u -- ) \ floating-ext
+: set-precision ( u -- ) \ float-ext
     \G Set the number of significant digits currently used by
-    \G @code{F.} @code{FE.} and @code{FS.} to @var{u}.
+    \G @code{F.} @code{FE.} and @code{FS.} to @i{u}.
     to precision ;
 
 : scratch ( r -- addr len )
@@ -103,8 +103,8 @@ DOES> ( -- r )
   IF  2drop  scratch 3 min type  rdrop  EXIT  THEN
   IF  '- emit  THEN ;
 
-: f.  ( r -- ) \ floating-ext f-dot
-\G Display (the floating-point number) @var{r} using fixed-point notation,
+: f.  ( r -- ) \ float-ext f-dot
+\G Display (the floating-point number) @i{r} using fixed-point notation,
 \G followed by a space.
   f$ dup >r 0<
   IF    '0 emit
@@ -114,14 +114,14 @@ DOES> ( -- r )
 \ I'm afraid this does not really implement ansi semantics wrt precision.
 \ Shouldn't precision indicate the number of places shown after the point?
 
-: fe. ( r -- ) \ floating-ext f-e-dot
-\G Display @var{r} using engineering notation, followed by a space.
+: fe. ( r -- ) \ float-ext f-e-dot
+\G Display @i{r} using engineering notation, followed by a space.
   f$ 1- s>d 3 fm/mod 3 * >r 1+ >r
   scratch r@ min type '. emit  scratch r> /string type
   'E emit r> . ;
 
-: fs. ( r -- ) \ floating-ext f-s-dot
-\G Display @var{r} using scientific notation, followed by a space.
+: fs. ( r -- ) \ float-ext f-s-dot
+\G Display @i{r} using scientific notation, followed by a space.
   f$ 1-
   scratch over c@ emit '. emit 1 /string type
   'E emit . ;
@@ -159,24 +159,24 @@ IS compiler-notfound
     ENDIF ;
 IS interpreter-notfound
 
-: fvariable ( "name" -- ) \ float
+: fvariable ( "name" -- ) \ float f-variable
     Create 0.0E0 f, ;
     \ does> ( -- f-addr )
 
 1.0e0 fasin 2.0e0 f* fconstant pi ( -- r ) \ gforth
-\G FCONSTANT: @var{r} is the value pi; the ratio of a circle's area
+\G @code{Fconstant} -- @i{r} is the value pi; the ratio of a circle's area
 \G to its diameter.
 
 : f2* ( r1 -- r2 ) \ gforth
-    \G Multiply @var{r1} by 2.0e0
+    \G Multiply @i{r1} by 2.0e0
     2.0e0 f* ;
 
 : f2/ ( r1 -- r2 ) \ gforth
-    \G Multiply @var{r1} by 0.5e0
+    \G Multiply @i{r1} by 0.5e0
     0.5e0 f* ;
 
 : 1/f ( r1 -- r2 ) \ gforth
-    \G Divide 1.0e0 by @var{r1}.
+    \G Divide 1.0e0 by @i{r1}.
     1.0e0 fswap f/ ;
 
 
@@ -193,20 +193,30 @@ IS interpreter-notfound
 \ : facosh   fdup fdup f* 1.0e0 f- fsqrt f+ fln ;
 \ : fasinh   fdup fdup f* 1.0e0 f+ fsqrt f/ fatanh ;
 
-\ !! factor out parts
-: f~ ( f1 f2 f3 -- flag ) \ float-ext
+: f~abs ( r1 r2 r3 -- flag ) \ gforth
+    \G Approximate equality with absolute error: |r1-r2|<r3.
+    frot frot f- fabs fswap f< ;
+
+: f~rel ( r1 r2 r3 -- flag ) \ gforth
+    \G Approximate equality with relative error: |r1-r2|<r3*|r1+r2|.
+	frot frot fover fabs fover fabs f+ frot frot
+	f- fabs frot frot f* f< ;
+
+: f~ ( r1 r2 r3 -- flag ) \ float-ext f-proximate
+    \G ANS Forth medley: r3>0: @code{f~abs}; r3=0: r1=r2; r3<0: @code{fnegate f~abs}.
     fdup f0=
     IF
-	fdrop f= EXIT
+	fdrop f=  \ !! this does not work, because 0=-0 with f= on Linux-Intel
+	          \ the standard says they should compare unequal
+		  \ the comparison should be done with COMPARE
+	EXIT
     THEN
     fdup f0>
     IF
-	frot frot f- fabs fswap
+	f~abs
     ELSE
-	fnegate frot frot fover fabs fover fabs f+ frot frot
-	f- fabs frot frot f*
-    THEN
-    f< ;
+	fnegate f~rel
+    THEN ;
 
 : f.s ( -- ) \ gforth f-dot-s
     \G Display the number of items on the floating-point stack,