PBC Library Manual 0.5.11 - Stanford Crypto Group

4.4. Element arithmetic
Chapter 4. Element functions
Unless otherwise stated, all element_t arguments to these functions must have been initialized to be
from the same algebraic structure. When one of these functions expects its arguments to be from
particular algebraic structures, this is reflected in the name of the function.
The addition and multiplication functions perform addition and multiplication operations in rings and
fields. For groups of points on an ellitpic curve, such as the G1 and G2 groups associated with pairings,
both addition and multiplication represent the group operation (and similarly both 0 and 1 represent the
identity element). It is recommended that programs choose and one convention and stick with it to avoid
confusion.
In contrast, the GT group is currently implemented as a subgroup of a finite field, so only multiplicative
operations should be used for GT.
void element_add(element_t n, element_t a, element_t b)
Set n to a + b.
void element_sub(element_t n, element_t a, element_t b)
Set n to a - b.
void element_mul(element_t n, element_t a, element_t b)
Set n = a b.
void element_mul_mpz(element_t n, element_t a, mpz_t z)
void element_mul_si(element_t n, element_t a, signed long int z)
Set n = a z, that is a + a + . . . + a where there are z a’s.
void element_mul_zn(element_t c, element_t a, element_t z)
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