make and curly braces

[Kenneth Almquist]

lois at hpfcdc.HP.COM (Lois Gerber) asks:
]  Does anyone know the historical reasons behind the following
]  reference on the make(1) man page:
]
] 	The -n option specifies printing of a command line without
] 	execution;  however, if the command line has the string
] 	$(MAKE) in it . . . . . . . the line is always executed.
] 	. . . . . Note that this feature does not work of MAKE
] 	is enclosed in braces, as in ${MAKE}. 
]
]  What was the past significance of curly braces in makefiles?

Curly braces are synonymous with parenthesis in many versions
of make.  I assume that the idea was to let the syntax of make
variables be more like the syntax of shell variables (after all,
why have two different syntaxes to do basicly the same thing?),
but this feature was never documented.
					Kenneth Almquist