Index - U
| unblock | Prelude.General |
| uncurry | Prelude.General |
| undefined | Prelude.General |
| UndefinedElement | Prelude.General |
| under | Prelude.General |
| Underflow | Prelude.General |
| unfolded | Prelude.General |
| unfoldr | Prelude.General |
| uninterruptibleMask | Prelude.General |
| uninterruptibleMask_ | Prelude.General |
| union | Prelude.General |
| unionBy | Prelude.General |
| universalNewlineMode | Prelude.General |
| universe | Prelude.General |
| universeOf | Prelude.General |
| universeOn | Prelude.General |
| universeOnOf | Prelude.General |
| unless | Prelude.General |
| unlines | Prelude.General |
| Unmasked | Prelude.General |
| unsafelyRestore | Prelude.General |
| unsafePartsOf | Prelude.General |
| unwords | Prelude.General |
| unwrapArrow | Prelude.General |
| unwrapMonad | Prelude.General |
| unzip | Prelude.General |
| unzip3 | Prelude.General |
| unzip4 | Prelude.General |
| unzip5 | Prelude.General |
| unzip6 | Prelude.General |
| unzip7 | Prelude.General |
| up | Prelude.General |
| use | Prelude.General |
| UserInterrupt | Prelude.General |
| uses | Prelude.General |
| utf16 | Prelude.General |
| utf16be | Prelude.General |
| utf16le | Prelude.General |
| utf32 | Prelude.General |
| utf32be | Prelude.General |
| utf32le | Prelude.General |
| utf8 | Prelude.General |
| utf8_bom | Prelude.General |