Patents use a specific language that must be understood by reading the patent several times, but everything must be clearly explained (so that at least the patent attorney understands this).
X, Y, and Z are probably reagent symbols for liquids (or gases) expressed in volumes, solids in masses or equivalents. You need to read the description carefully, because equivalents may have a different meaning from moles.
After reading a dozen or so patents, you will start to understand it without reading again and you'll know where to look for (hidden) explanations.