KOS_OP_PARAM

• Style: EXTRA. Schema CONST (parameter name), COUNT (0 or 1 stacked defaults).

• Stack: [] → [value] at count 0; [default] → [value] at count 1.

• Resolves: the enclosing parameterize extent (the context’s shadow table), then the root scope of the context’s domain. Writes to neither, and creates no entry on a miss.

• Invariants: On a miss at count 0, raises NameError. At count 1 the stacked default answers a miss, and is dropped on a hit.

• Example: (parameterq x) compiles to PARAM ("x", 0); (parameterq x (compute)) compiles the expression, then PARAM ("x", 1).

index	opcode	arg	arg view	comment
0	CONST	0	“fallback”	push the default
1	PARAM	0	(“x”, 1)	resolve x, else keep default