Which distinction concerning fasting and ghusl is correct?

Four Modes of Textual Indication: ʿIbārah, Ishārah, Dalālah and Iqtiḍāʾ

• Ghusl is never required after janābah
• Prayer is valid without ghusl
• An obligation of ghusl necessarily invalidates the fast
• Ghusl may be required, but its delay alone does not invalidate fasting