Update docs

Author: odersky

docs/docs/reference/contextual/inferable-params.md

@@ -41,8 +41,7 @@ def maximum[T](xs: List[T]) given Ord[T]: T =
 inferred argument to `max`. The name of the parameter is left out.
 
 Generally, inferable parameters may be given either as a parameter list `(p_1: T_1, ..., p_n: T_n)`
-or as a sequence of types, separated by commas. To distinguish the two, a leading
-`(` always indicates a parameter list.
+or as a sequence of types, separated by commas.
 
 ## Inferring Complex Arguments
 
@@ -105,7 +104,7 @@ ClsParamClause    ::=  ...
 DefParamClause    ::=  ...
                     |  GivenParamClause
 GivenParamClause  ::=  ‘given’ (‘(’ DefParams ‘)’ | GivenTypes)
-GivenTypes        ::=  RefinedType {‘,’ RefinedType}
+GivenTypes        ::=  AnnotType {‘,’ AnnotType}
 
 InfixExpr         ::=  ...
                     |  InfixExpr ‘given’ (InfixExpr | ParArgumentExprs)

docs/docs/reference/contextual/instance-defs.md

@@ -68,10 +68,10 @@ TmplDef          ::=  ...
                   |  ‘implied’ InstanceDef
 InstanceDef      ::=  [id] InstanceParams InstanceBody
 InstanceParams   ::=  [DefTypeParamClause] {GivenParamClause}
-InferParamClause ::=  ‘given’ (‘(’ [DefParams] ‘)’ | GivenTypes)
+GivenParamClause ::=  ‘given’ (‘(’ [DefParams] ‘)’ | GivenTypes)
 InstanceBody     ::=  [‘for’ ConstrApp {‘,’ ConstrApp }] [TemplateBody]
                    |  ‘for’ Type ‘=’ Expr
-GivenTypes       ::=  RefinedType {‘,’ RefinedType}
+GivenTypes       ::=  AnnotType {‘,’ AnnotType}
 ```
 The identifier `id` can be omitted only if either the `for` part or the template body is present.
 If the `for` part is missing, the template body must define at least one extension method.