That definitely must've been an error, especially considering (1+p) already takes into account both the nominal interest rate (r) and inflation (pi).
The future value constraint is
(1+p)c1 + c2 = (1+p)m1 + m2
or alternatively,
[(1+r)/(1+pi)]*c1 + c2 = [(1+r)/(1+pi)]*m1 + m2
If we're only talking in nominal terms, you can forgo pi.