10 REM A field name is checked against the type's closed set, which
20 REM is the one thing here whose valid spellings are written down.
30 REM A misspelled *variable* is still silent -- see the last two lines.
40 TYPE RECT
50   W#
60   H#
70 END TYPE
80 DIM R@ AS RECT
90 R@.W# = 3
100 PRINT R@.W#
110 REM A variable nobody assigned is zero, with no complaint at all.
120 PRINT TOTLA#
130 REM A field the type does not declare is refused, and lists the real ones.
140 PRINT R@.NOPE#
