-USING: help.markup help.syntax math.functions ;
+USING: help.markup help.syntax math math.functions ;
 IN: math.derivatives
 
 HELP: derivative ( x function -- m )
-{ $values { "x" "a position on the function" } { "function" "a differentiable function" } }
+{ $values { "x" "a position on the function" } { "function" "a differentiable function" } { "m" number } }
 { $description
     "Approximates the slope of the tangent line by using Ridders' "
     "method of computing derivatives, from the chapter \"Accurate computation "

    }
} ;

HELP: derivative-func ( function -- der )
{ $values { "func" "a differentiable function" } { "der" "the derivative" } }
{ $description
    "Provides the derivative of the function. The implementation simply "

{ $examples
    { $example
        "USING: math math.derivatives prettyprint ;"
        "4 [ sq ] derivative >integer ."
        "8"
    }
    { $notes
