In general
Gross income of a lessee does not include any amount received in cash (or treated as a rent reduction) by a lessee from a lessor—
(1)#
under a short-term lease of retail space, and
(2)#
for the purpose of such lessee’s constructing or improving qualified long-term real property for use in such lessee’s trade or business at such retail space,
but only to the extent that such amount does not exceed the amount expended by the lessee for such construction or improvement.