1. A demonstrable proposition is comprehended when known by demonstration.

2. 7 Principle of Parsimony: Write large components only when it is clear by demonstration that nothing else will do.

3. Diagnosis of kala-azar is accomplished either by demonstration of amastigotes (LD bodies; Aflagellar forms) in splenic or bone marrow smears or by culture of leishmania promastigotes (flagellar forms) from clinical specimen (most commonly in NNN media)