Question 1047235
{{{ p^(m-n)*q^(n-l)*r^(l-m)}}}

= {{{(x^(m+n)*y)^(m-n)*( x^(n+1)*y^m) ^(n-l)* (x^(1+m)*y^n)^(l-m)}}}

= {{{x^(m^2-n^2)*y^(m-n)*x^(n^2-1)*y^(mn-m)*x^(1-m^2)*y^(n-mn)}}}

= {{{x^(m^2-n^2+n^2-1+1-m^2)*y^(m-n+mn-m+n-mn)}}}

= {{{x^0*y^0 = 1}}}.