The Hobbit (v1.0): Routine at 7DD5

AND (or a comma) is ambiguous: it may join two objects ('take the key and the sword') or two commands ('take the key and go east'). The parser cannot tell until it sees what follows, so it records where it is: the token pointer (in 7C3E and $B5CD, pointing back at the AND), the state flags E ($7C40), the frame pointer IY ($7C41) and the frame count ($7C43). It then carries on as though a new command had begun (7CC4). If a verb turns up next, the new command stands. If not, the verb handler at 7DFD is never reached and the next frame inherits the verb of this one (7F81).

Bit 3 of E is reset to show that an AND has just been seen.

AND (or a comma) is ambiguous: it may join two objects ('take the key and the sword') or two commands ('take the key and go east'). The parser cannot tell until it sees what follows, so it records where it is: the token pointer (in 7C3E and $B5CD, pointing back at the AND), the state flags E ($7C40), the frame pointer IY ($7C41) and the frame count ($7C43). It then carries on as though a new command had begun (7CC4). If a verb turns up next, the new command stands. If not, the verb handler at 7DFD is never reached and the next frame inherits the verb of this one (7F81). Bit 3 of E is reset to show that an AND has just been seen.
7DD5	RES 3,E	Note that AND has been seen (bit 3 clear)
7DD7	PUSH DE	Note that AND has been seen (bit 3 clear)
7DD8	CALL $7F3D	Skip any further ANDs and commas
7DDB	CP $A0
7DDD	JR Z,$7DD8
7DDF	DEC HL	Step back so the word after them will be read again
7DE0	DEC HL	Step back so the word after them will be read again
7DE1	LD ($7C3E),HL	Save the token pointer...
7DE4	LD ($B5CD),HL
7DE7	POP DE
7DE8	LD A,E	...the state flags...
7DE9	LD ($7C40),A	...the state flags...
7DEC	LD ($7C41),IY	...the frame pointer...
7DF0	LD A,($B5F7)	...and the frame count, so the parser can backtrack here
7DF3	LD ($7C43),A	...and the frame count, so the parser can backtrack here
7DF6	JP $7CC4	Then carry on as if a new command were starting