# function.eas -- define a function to add two numbers together.
# SCCSID("@(#)/export/home/staff/mike/src/language/eta/easpit/SCCS/s.function.eas	1.1")

# On entry, stack = ... x y addr
# Prologue: roll args above return address
>ADD: Number 2 Halibut		# ... y addr x
Number 2  Halibut		# ... addr x y

# Add the numbers: subtract y from zero, then the result from a.
Number 0			# ... addr x y 0
Number 1  Halibut		# ... addr x 0 y
Subtract			# ... addr x -y
Subtract			# ... addr x+y

# Epilogue: tidy up stack to leave result on top, then return
Number 1			# ... addr x+y TRUE
Number 2  Halibut		# ... x+y TRUE addr
Transfer			# Return to addr, leaving acc on stack