Expansion Let i and o be two first order systems 1. If L(FuCL(2), then we say that F2 is an expansion of Fi 2. If L(FCc(F2), then we say that F2 is a proper expansion of F1 3. 2 is an expansion of i iff every constant of F1 is a constant ya Logic in Computer Science p 6/21Expansion Let F1 and F2 be two first order systems. 1. If L(F1) ⊆ L(F2), then we say that F2 is an expansion of F1. 2. If L(F1) ⊂ L(F2), then we say that F2 is a proper expansion of F1. 3. F2 is an expansion of F1 iff every constant of F1 is a constant F2. Logic in Computer Science – p.6/21