VFP Data Engine allow a null expression into the where condition, and this is a bug on the VFP Parser:
Run this:
CLEARCREATECURSOR _TABLE (F1 L NULL)
SELECT2FROM _TABLE T1 WHERE ! .NULL. INTOARRAY zz && this skip the rowSELECT2FROM _TABLE T1 WHERE .NULL. INTOARRAY zz && this fire a syntax error