Two programs P and Q are partially equivalent if, when both terminate on the same input, they end up with equivalent outputs. Establishing partial equivalence is useful in, e.g., Compiler verification, when P is the source program and Q is the target program, or in compiler optimisation, when P is the initial program and Q is the optimised program. A program R is partially correct if, when it terminates, it ends up in a "good" state. We show that, somewhat surprisingly, the problem of establishing partial equivalence can be reduced to the problem of showing partial correctness in an aggregated language, where programs R consist of pairs of programs