${VAR} = "foo  bar baz"
a
b
c
foo baR baz,  bar baz, foo bar baz, fooadd baradd bazadd
mkdir -p 'dir'
touch 'dir/obj_1.h'
mkdir -p 'dir'
printf '#include "obj_1.h"\nconst char* obj_1 = "dir/obj_1.c";\n' \
    >'dir/obj_1.c'
Local variables
 ${@}="dir/obj_1.o" ${<}="dir/obj_1.c"
 ${*}="dir/obj_1" ${?}="dir/obj_1.h dir/obj_1.c"
 ${%}=""

Directory and filename parts of local variables
 ${@D}="dir" ${@F}="obj_1.o"
 ${<D}="dir" ${<F}="obj_1.c"
 ${*D}="dir" ${*F}="obj_1"
 ${?D}="dir dir" ${?F}="obj_1.h obj_1.c"
 ${%D}="" ${%F}=""

Local variable substitutions
 ${@:.o=}="dir/obj_1" ${<:.c=.C}="dir/obj_1.C"
 ${*:=.h}="dir/obj_1.h" ${?:.h=.H}="dir/obj_1.H dir/obj_1.c"
 ${%:=}=""

Target with suffix transformations
 ${@D:=append}="dirappend"
 ${@F:.o=.O}="obj_1.O"
 
 Implied source with suffix transformations
 ${<D:r=rr}="dirr"
 ${<F:.c=.C}="obj_1.C"
 
 Suffixless target with suffix transformations
 ${*D:.=dot}="dir"
 ${*F:.a=}="obj_1"
 
 Out-of-date dependencies with suffix transformations
 ${?D:ir=}="d d"
 ${?F:.h=.H}="obj_1.H obj_1.c"
 
 Member with suffix transformations
 ${%D:.=}=""
 ${%F:${VAR2}=${VAR}}=""

cc -c -o 'dir/obj_1.o' 'dir/obj_1.c'
mkdir -p '.'
touch 'dummy'
Local variables
 ${@}="lib.a" ${<}="dir/obj_1.o"
 ${*}="obj1" ${?}="dir/obj_1.o dummy"
 ${%}="obj1.o"

Directory and filename parts of local variables
 ${@D}="." ${@F}="lib.a"
 ${<D}="dir" ${<F}="obj_1.o"
 ${*D}="." ${*F}="obj1"
 ${?D}="dir ." ${?F}="obj_1.o dummy"
 ${%D}="." ${%F}="obj1.o"

Local variable substitutions
 ${@:.o=}="lib.a" ${<:.c=.C}="dir/obj_1.o"
 ${*:=.h}="obj1.h" ${?:.h=.H}="dir/obj_1.o dummy"
 ${%:=}="obj1.o"

Target with suffix transformations
 ${@D:=append}=".append"
 ${@F:.o=.O}="lib.a"
 
 Implied source with suffix transformations
 ${<D:r=rr}="dirr"
 ${<F:.c=.C}="obj_1.o"
 
 Suffixless target with suffix transformations
 ${*D:.=dot}="dot"
 ${*F:.a=}="obj1"
 
 Out-of-date dependencies with suffix transformations
 ${?D:ir=}="d ."
 ${?F:.h=.H}="obj_1.o dummy"
 
 Member with suffix transformations
 ${%D:.=}=""
 ${%F:${VAR2}=${VAR}}="obj1foo  bar baz"

cp 'dir/obj_1.o' 'obj1.o'
ar -rcv 'lib.a' 'obj1.o'
a - obj1.o
rm -f 'obj1.o'
mkdir -p '.'
printf '#include "obj_2.h"\nconst char* obj_2 = "obj_2.c";\n' \
    >'obj_2.c'
mkdir -p '.'
touch 'obj_2.h'
Local variables
 ${@}="obj2.o" ${<}="obj_2.c"
 ${*}="obj2" ${?}="obj_2.c obj_2.h dir/obj_1.h"
 ${%}=""

Directory and filename parts of local variables
 ${@D}="." ${@F}="obj2.o"
 ${<D}="." ${<F}="obj_2.c"
 ${*D}="." ${*F}="obj2"
 ${?D}=". . dir" ${?F}="obj_2.c obj_2.h obj_1.h"
 ${%D}="" ${%F}=""

Local variable substitutions
 ${@:.o=}="obj2" ${<:.c=.C}="obj_2.C"
 ${*:=.h}="obj2.h" ${?:.h=.H}="obj_2.c obj_2.H dir/obj_1.H"
 ${%:=}=""

Target with suffix transformations
 ${@D:=append}=".append"
 ${@F:.o=.O}="obj2.O"
 
 Implied source with suffix transformations
 ${<D:r=rr}="."
 ${<F:.c=.C}="obj_2.C"
 
 Suffixless target with suffix transformations
 ${*D:.=dot}="dot"
 ${*F:.a=}="obj2"
 
 Out-of-date dependencies with suffix transformations
 ${?D:ir=}=". . d"
 ${?F:.h=.H}="obj_2.c obj_2.H obj_1.H"
 
 Member with suffix transformations
 ${%D:.=}=""
 ${%F:${VAR2}=${VAR}}=""

cc -c -o 'obj2.o' 'obj_2.c'
ar -rcv 'lib.a' 'obj2.o'
a - obj2.o
mkdir -p '.'
touch 'obj3.h'
mkdir -p 'dir'
touch 'dir/dummy'
mkdir -p '.'
printf '#include "obj3.h"\nconst char* obj3 = "obj3.c";\n' \
    >'obj3.c'
Local variables
 ${@}="lib.a" ${<}="obj3.c"
 ${*}="obj3" ${?}="obj3.h dir/dummy obj3.c"
 ${%}="obj3.o"

Directory and filename parts of local variables
 ${@D}="." ${@F}="lib.a"
 ${<D}="." ${<F}="obj3.c"
 ${*D}="." ${*F}="obj3"
 ${?D}=". dir ." ${?F}="obj3.h dummy obj3.c"
 ${%D}="." ${%F}="obj3.o"

Local variable substitutions
 ${@:.o=}="lib.a" ${<:.c=.C}="obj3.C"
 ${*:=.h}="obj3.h" ${?:.h=.H}="obj3.H dir/dummy obj3.c"
 ${%:=}="obj3.o"

Target with suffix transformations
 ${@D:=append}=".append"
 ${@F:.o=.O}="lib.a"
 
 Implied source with suffix transformations
 ${<D:r=rr}="."
 ${<F:.c=.C}="obj3.C"
 
 Suffixless target with suffix transformations
 ${*D:.=dot}="dot"
 ${*F:.a=}="obj3"
 
 Out-of-date dependencies with suffix transformations
 ${?D:ir=}=". d ."
 ${?F:.h=.H}="obj3.H dummy obj3.c"
 
 Member with suffix transformations
 ${%D:.=}=""
 ${%F:${VAR2}=${VAR}}="obj3foo  bar baz"

cc -c -o 'obj3.o' 'obj3.c'
ar -rcv 'lib.a' 'obj3.o'
a - obj3.o
rm -f 'obj3.o'
ar -s 'lib.a'
exit status 0