  G. Godefroy and the second author of this note proved in 1988 that in duals
to Asplund spaces there always exists a projectional resolution of the
identity. A few years later, Ch. Stegall succeeded to drop from the original
proof a deep lemma of S. Simons. Here, we rewrite the condensed argument of Ch.
Stegall in a more transparent and detailed way. We actually show that this
technology of Ch. Stegall leads to a bit stronger/richer object ---the so
called projectional skeleton--- recently constructed by W. Kubi\'s, via S.
Simons' lemma and with help of elementary submodels from logic.
