reserve SOURCE for non empty finite set,
 p for Probability of Trivial-SigmaField SOURCE,
 Tseq for FinSequence of BoolBinFinTrees IndexedREAL,
 q for FinSequence of NAT;

theorem Th15:
 Leaves (elementary_tree 0 ) = elementary_tree 0
proof
for x be object holds
 x in Leaves (elementary_tree 0 ) iff x in elementary_tree 0
proof
 let x be object;
 thus x in Leaves (elementary_tree 0 ) implies x in elementary_tree 0;
assume x in elementary_tree 0; then
 reconsider x0=x as Element of elementary_tree 0;
 not x0 ^ <* 0 *> in elementary_tree 0 by TREES_1:29,TARSKI:def 1;
 hence x in Leaves (elementary_tree 0 ) by TREES_1:54;
end;
hence thesis by TARSKI:2;
end;
