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fix(library/elaborator): the context of auxiliary metavariables created in the imitation step was incorrect

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Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit is contained in:
Leonardo de Moura 2013-12-11 12:35:32 -08:00
parent 55389cf6e5
commit 1d33d3b5db
1 changed files with 18 additions and 15 deletions
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33
src/library/elaborator/elaborator.cpp
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@ -737,10 +737,12 @@ class elaborator::imp {
unsigned num_a = num_args(a);
buffer<expr> arg_types;
buffer<unification_constraint> ucs;
context h_ctx = ctx; // context for new fresh metavariables used in the imitation step
for (unsigned i = 1; i < num_a; i++) {
arg_types.push_back(m_type_inferer(arg(a, i), ctx, &menv, &ucs));
for (auto uc : ucs)
push_front(uc);
h_ctx = extend(h_ctx, name(g_x_name, i), arg_types.back());
}
// Add projections
for (unsigned i = 1; i < num_a; i++) {
@ -765,42 +767,43 @@ class elaborator::imp {
// Imitation for applications
expr f_b = arg(b, 0);
unsigned num_b = num_args(b);
// Assign f_a <- fun (x_1 : T_0) ... (x_{num_a-1} : T_{num_a-1}), f_b (h_1 x_1 ... x_{num_a-1}) ... (h_{num_b-1} x_1 ... x_{num_a-1})
// New constraints (h_i a_1 ... a_{num_a-1}) == arg(b, i)
// Assign f_a <- fun (x_1 : T_1) ... (x_{num_a} : T_{num_a}), f_b (h_1 x_1 ... x_{num_a}) ... (h_{num_b} x_1 ... x_{num_a})
// New constraints (h_i a_1 ... a_{num_a}) == arg(b, i)
buffer<expr> imitation_args; // arguments for the imitation
imitation_args.push_back(lift_free_vars(f_b, 0, num_a - 1));
for (unsigned i = 1; i < num_b; i++) {
expr h_i = new_state.m_menv.mk_metavar(ctx);
// Remark: h_ctx is "ctx, (x_{num_a} : T_{num_a}) ... (x_1 : T_1)" because h_i is inside of the lambda
expr h_i = new_state.m_menv.mk_metavar(h_ctx);
imitation_args.push_back(mk_app_vars(h_i, num_a - 1));
push_new_eq_constraint(new_state.m_queue, ctx, update_app(a, 0, h_i), arg(b, i), new_assumption);
}
imitation = mk_lambda(arg_types, mk_app(imitation_args));
} else if (is_eq(b)) {
// Imitation for equality
// Assign f_a <- fun (x_1 : T_0) ... (x_{num_a-1} : T_{num_a-1}), (h_1 x_1 ... x_{num_a-1}) = (h_2 x_1 ... x_{num_a-1})
// New constraints (h_1 a_1 ... a_{num_a-1}) == eq_lhs(b)
// (h_2 a_1 ... a_{num_a-1}) == eq_rhs(b)
expr h_1 = new_state.m_menv.mk_metavar(ctx);
expr h_2 = new_state.m_menv.mk_metavar(ctx);
// Assign f_a <- fun (x_1 : T_1) ... (x_{num_a} : T_{num_a}), (h_1 x_1 ... x_{num_a}) = (h_2 x_1 ... x_{num_a})
// New constraints (h_1 a_1 ... a_{num_a}) == eq_lhs(b)
// (h_2 a_1 ... a_{num_a}) == eq_rhs(b)
expr h_1 = new_state.m_menv.mk_metavar(h_ctx);
expr h_2 = new_state.m_menv.mk_metavar(h_ctx);
push_new_eq_constraint(new_state.m_queue, ctx, update_app(a, 0, h_1), eq_lhs(b), new_assumption);
push_new_eq_constraint(new_state.m_queue, ctx, update_app(a, 0, h_2), eq_rhs(b), new_assumption);
imitation = mk_lambda(arg_types, mk_eq(mk_app_vars(h_1, num_a - 1), mk_app_vars(h_2, num_a - 1)));
} else if (is_abstraction(b)) {
// Imitation for lambdas and Pis
// Assign f_a <- fun (x_1 : T_0) ... (x_{num_a-1} : T_{num_a-1}),
// fun (x_b : (?h_1 x_1 ... x_{num_a-1})), (?h_2 x_1 ... x_{num_a-1} x_b)
// New constraints (h_1 a_1 ... a_{num_a-1}) == abst_domain(b)
// (h_2 a_1 ... a_{num_a-1} x_b) == abst_body(b)
expr h_1 = new_state.m_menv.mk_metavar(ctx);
// Assign f_a <- fun (x_1 : T_1) ... (x_{num_a} : T_{num_a}),
// fun (x_b : (?h_1 x_1 ... x_{num_a})), (?h_2 x_1 ... x_{num_a} x_b)
// New constraints (h_1 a_1 ... a_{num_a}) == abst_domain(b)
// (h_2 a_1 ... a_{num_a} x_b) == abst_body(b)
expr h_1 = new_state.m_menv.mk_metavar(h_ctx);
context new_ctx = extend(ctx, abst_name(b), abst_domain(b));
expr h_2 = new_state.m_menv.mk_metavar(new_ctx);
expr h_2 = new_state.m_menv.mk_metavar(extend(h_ctx, abst_name(b), abst_domain(b)));
push_new_eq_constraint(new_state.m_queue, ctx, update_app(a, 0, h_1), abst_domain(b), new_assumption);
push_new_eq_constraint(new_state.m_queue, new_ctx,
mk_app(update_app(a, 0, h_2), mk_var(0)), abst_body(b), new_assumption);
imitation = mk_lambda(arg_types, update_abstraction(b, mk_app_vars(h_1, num_a - 1), mk_app_vars(h_2, num_a)));
} else {
// "Dumb imitation" aka the constant function
// Assign f_a <- fun (x_1 : T_0) ... (x_{num_a-1} : T_{num_a-1}), b
// Assign f_a <- fun (x_1 : T_1) ... (x_{num_a} : T_{num_a}), b
imitation = mk_lambda(arg_types, lift_free_vars(b, 0, num_a - 1));
}
push_new_eq_constraint(new_state.m_queue, ctx, f_a, imitation, new_assumption);