x1=z1=s1 is more exact/precise than x2=z2 is in property / quantity x3=s3 by amount / excess x4=z4.
satcymau uses «-mau» to insert zmadu2 at x2 (and append zmadu4; see also fi'o) (this lujvo construction also adapts zmadu3 to satci2 rather than a relationship that includes it, making it slightly less regular, since it's much more useful and the alternative doesn't seem very useful; see also the difference between zmanei and nelmau). See also: satcyme'a.