Exercise: assume that there are two entities in the domain of
discourse, Alice and Bob. Assume that Alice is a woman, and Bob is a
-man. Show the following computations:
+man. Show the following computations, where `i = (w,n,r,g)`:
+
+ 1. {i}[∃x.person(x)]
+
+ = {(w,n+1,r[x->n],g[n->a]),(w,n+1,r[x->n],g[n->b])}[person(x)]
+ = {(w,n+1,r[x->n],g[n->a]),(w,n+1,r[x->n],g[n->b])}
+
+ 2. {i}[∃x.man(x)]
+
+ = {(w,n+1,r[x->n],g[n->a]),(w,n+1,r[x->n],g[n->b])}[person(x)]
+ = {(w,n+1,r[x->n],g[n->b])}
+
+
+ 3. {i}[∃x∃y.person(x) and person(y)]
+
+ = {(w,n+1,r[x->n],g[n->a]),(w,n+1,r[x->n],g[n->b])}[∃y.person(x) and person(y)]
+ = {(w, n+2, r[x->n][y->n+1], g[n->a][n+1->a]),
+ (w, n+2, r[x->n][y->n+1], g[n->a][n+1->b]),
+ (w, n+2, r[x->n][y->n+1], g[n->b][n+1->a]),
+ (w, n+2, r[x->n][y->n+1], g[n->b][n+1->b])
+ }[person(x) and person(y)]
+ = {(w, n+2, r[x->n][y->n+1], g[n->a][n+1->a]),
+ (w, n+2, r[x->n][y->n+1], g[n->a][n+1->b]),
+ (w, n+2, r[x->n][y->n+1], g[n->b][n+1->a]),
+ (w, n+2, r[x->n][y->n+1], g[n->b][n+1->b])
+ }
+
+ 4. {i}[∃x∃y.x=x]
+
+ = {(w, n+2, r[x->n][y->n+1], g[n->a][n+1->a]),
+ (w, n+2, r[x->n][y->n+1], g[n->a][n+1->b]),
+ (w, n+2, r[x->n][y->n+1], g[n->b][n+1->a]),
+ (w, n+2, r[x->n][y->n+1], g[n->b][n+1->b])
+ }[∃x∃y.x=x]
+ = {(w, n+2, r[x->n][y->n+1], g[n->a][n+1->a]),
+ (w, n+2, r[x->n][y->n+1], g[n->a][n+1->b]),
+ (w, n+2, r[x->n][y->n+1], g[n->b][n+1->a]),
+ (w, n+2, r[x->n][y->n+1], g[n->b][n+1->b])
+ }
+
+ 5. {i}[∃x∃y.x=y]
+
+ = {(w, n+2, r[x->n][y->n+1], g[n->a][n+1->a]),
+ (w, n+2, r[x->n][y->n+1], g[n->a][n+1->b]),
+ (w, n+2, r[x->n][y->n+1], g[n->b][n+1->a]),
+ (w, n+2, r[x->n][y->n+1], g[n->b][n+1->b])
+ }[∃x∃y.x=y]
+ = {(w, n+2, r[x->n][y->n+1], g[n->a][n+1->a]),
+ (w, n+2, r[x->n][y->n+1], g[n->b][n+1->b])
+ }
- 1. {}[∃x.person(x)]
- 2. {}[∃x.man(x)]
- 3. {}[∃x∃y.person(x) and person(y)]
- 4. {}[∃x∃y.x=x]
- 5. {}[∃x∃y.x=y]