{ "name": "Cardinality of sets", "order": 13, "challenges": [ { "id": "59a5801209a6acac5983b610", "title": "Sets with equal cardinalities", "description": [ "" ], "challengeSeed": [ "" ], "tests": [ "" ] }, { "id": "59a5801209a6acac5983a946", "title": "Countable and uncountable sets", "description": [ "" ], "challengeSeed": [ "" ], "tests": [ "" ] }, { "id": "59a5801209a6acac5983a947", "title": "Comparing cardinalities", "description": [ "" ], "challengeSeed": [ "" ], "tests": [ "" ] }, { "id": "59a5801209a6acac5983a948", "title": "The Cantor-Bernstein-Schroeder Theorem", "description": [ "" ], "challengeSeed": [ "" ], "tests": [ "" ] } ] }