plz Help me with this: Assignment has more non-singleton rhs dimensions than non-singleton subscripts

eqn1= p-((1/(y1/ps1))+(1/(y2/ps2)))==0;

Error:

Assignment has more non-singleton rhs dimensions than non-singleton subscripts

[Walter Roberson]

Not on that line — not unless one of the names there is a function and has a problem inside it.