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Mirrors > Home > MPE Home > Th. List > df-mnd | Structured version Visualization version Unicode version |
Description: A monoid is a semigroup, which has a two-sided neutral element. Definition 2 in [BourbakiAlg1] p. 12. In other words (according to the definition in [Lang] p. 3), a monoid is a set equipped with an everywhere defined internal operation (see mndcl 17301), whose operation is associative (see mndass 17302) and has a two-sided neutral element (see mndid 17303), see also ismnd 17297. (Contributed by Mario Carneiro, 6-Jan-2015.) (Revised by AV, 1-Feb-2020.) |
Ref | Expression |
---|---|
df-mnd | SGrp |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cmnd 17294 | . 2 | |
2 | ve | . . . . . . . . . . 11 | |
3 | 2 | cv 1482 | . . . . . . . . . 10 |
4 | vx | . . . . . . . . . . 11 | |
5 | 4 | cv 1482 | . . . . . . . . . 10 |
6 | vp | . . . . . . . . . . 11 | |
7 | 6 | cv 1482 | . . . . . . . . . 10 |
8 | 3, 5, 7 | co 6650 | . . . . . . . . 9 |
9 | 8, 5 | wceq 1483 | . . . . . . . 8 |
10 | 5, 3, 7 | co 6650 | . . . . . . . . 9 |
11 | 10, 5 | wceq 1483 | . . . . . . . 8 |
12 | 9, 11 | wa 384 | . . . . . . 7 |
13 | vb | . . . . . . . 8 | |
14 | 13 | cv 1482 | . . . . . . 7 |
15 | 12, 4, 14 | wral 2912 | . . . . . 6 |
16 | 15, 2, 14 | wrex 2913 | . . . . 5 |
17 | vg | . . . . . . 7 | |
18 | 17 | cv 1482 | . . . . . 6 |
19 | cplusg 15941 | . . . . . 6 | |
20 | 18, 19 | cfv 5888 | . . . . 5 |
21 | 16, 6, 20 | wsbc 3435 | . . . 4 |
22 | cbs 15857 | . . . . 5 | |
23 | 18, 22 | cfv 5888 | . . . 4 |
24 | 21, 13, 23 | wsbc 3435 | . . 3 |
25 | csgrp 17283 | . . 3 SGrp | |
26 | 24, 17, 25 | crab 2916 | . 2 SGrp |
27 | 1, 26 | wceq 1483 | 1 SGrp |
Colors of variables: wff setvar class |
This definition is referenced by: ismnddef 17296 |
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