| basis(cause, source, foundation, basic) |
| foundation(cause, source, basic, origin) |
| principle(foundation, basic, stipulation, tenet) |
| rudiment(foundation, basic, stipulation, tenet) |
| bottom line(expression, foundation, basic, stipulation) |
| brass tacks(expression, foundation, basic, stipulation) |
| coal and ice(expression, idiom, foundation, basic) |
| essential part(expression, foundation, basic, stipulation) |
| heart(cause, source, foundation, basic) |
| sine qua non(expression, idiom, foundation, basic) |
| ABCs(foundation, basic, stipulation, tenet) |
| axiom(foundation, basic, stipulation, tenet) |
| basic(foundation, stipulation, tenet, axiom) |
| component(foundation, basic, stipulation, tenet) |
| constituent(foundation, basic, stipulation, tenet) |
| cornerstone(foundation, basic, stipulation, tenet) |
| element(foundation, basic, stipulation, tenet) |
| factor(foundation, basic, stipulation, tenet) |
| guts(foundation, basic, stipulation, tenet) |
| nitty-gritty(foundation, basic, stipulation, tenet) |