Remove Base module identifier from length(::BasicSymbolic) method

Author: bowenszhu

src/utils.jl

@@ -183,7 +183,7 @@ Base.length(l::LL) = length(l.v)-l.i+1
 @inline car(l::LL) = l.v[l.i]
 @inline cdr(l::LL) = isempty(l) ? empty(l) : LL(l.v, l.i+1)
 
-function Base.length(t::BasicSymbolic)
+function length(t::BasicSymbolic)
     @match t.impl begin
         Term(_...) => length(arguments(t)) + 1 # PIRACY
         _ => 1