Description: A true statement is true upon substitution (deduction). A similar proof is possible for icht . (Contributed by SN, 4-May-2024)
Ref | Expression | ||
---|---|---|---|
Hypothesis | sbtd.1 | ||
Assertion | sbtd |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sbtd.1 | ||
2 | 1 | alrimiv | |
3 | stdpc4 | ||
4 | 2 3 | syl |