a := 1
a := 1 a.minimum := -2
a.maximum := 2
b := 1
b.minimum := -2
b.maximum := 2
c := 1
c.minimum := -2
c.maximum := 2
d := 1
d.minimum := -2
d.maximum := 2
graph3d.box := false
graph3d.mesh := true
graph3d.view := standard
graph3d.background := black
graph3d.perspective := true
graph3d.resolution := 21
graph3d.highlight := true
graph3d.shading := true
graph3d.contrast := 1/2
graph3d.transparency := .5
graph3d.color := cos(x)*sin(y)
graph3d.minimumx := -3
graph3d.maximumx := 3
graph3d.minimumy := -3
graph3d.maximumy := 3
graph3d.minimumu := 0
graph3d.maximumu := 6.28
graph3d.minimumv := 0
graph3d.maximumv := 6.28
graph3d.stepsu := 50
graph3d.stepsv := 50
graph3d(rectangular(
.707*cos(u+v)/(1.0-.707*sin(u-v)),
.707*sin(u+v)/(1.0-.707*sin(u-v)),
.707*cos(u-v)/(1.0-.707*sin(u-v)))
)