// Souffle - A Datalog Compiler
// Copyright (c) 2018, The Souffle Developers. All rights reserved
// Licensed under the Universal Permissive License v 1.0 as shown at:
// - https://opensource.org/licenses/UPL
// - <souffle root>/licenses/SOUFFLE-UPL.txt

// Tests the use of singleton variables

.decl a(x:number)
a(0).

.decl b(x:number)

.decl query(x:symbol)
.output query()
query("t1") :- a(x).
query("t2") :- a(_x).
query("t3") :- a(_).
query("t4") :- b(x).
query("t5") :- b(_x).
query("t6") :- b(_).
query("t7") :- a(x), b(y).
query("t8") :- a(x), a(y).
query("t9") :- b(x), b(y).
