FILTER_CONV : conv -> conv
STRUCTURE
listLib
SYNOPSIS
Computes by inference the result of applying a predicate to the elements of a list.
DESCRIPTION
FILTER_CONV takes a conversion conv and a term tm in the following form: 
   FILTER P [x0;...xn]
It returns the theorem 
   |- FILTER P [x0;...xn] = [...xi...]
where for every xi occurring in the right-hand side of the resulting theorem, conv “P xi” returns a theorem |- P xi = T.
FAILURE
FILTER_CONV conv tm fails if tm is not of the form described above.
EXAMPLE
Evaluating 
   FILTER_CONV bool_EQ_CONV “FILTER ($= T) [T;F;T]”;
returns the following theorem: 
   |- FILTER($= T)[T;F;T] = [T;T]
In general, if the predicate P is an explicit lambda abstraction (\x. P x), the conversion should be in the form 
   (BETA_CONV THENC conv')
SEEALSO
FOLDL_CONV, FOLDR_CONV, list_FOLD_CONV
HOL  Kananaskis-13